Channel state information concatenation and antenna port measurement

ABSTRACT

Herein described are apparatuses, systems, and methods for measurement and reporting of channel state information within wireless network systems. In embodiments, an apparatus for a user equipment (UE) may include memory to store a rank indicator (RI), a precoding matrix index (PMI), and a channel quality indicator (CQI) of channel state information (CSI) for the UE. The apparatus may further include circuitry to concatenate the RI, the PMI, and the CQI to produce a concatenated CSI element, generate a CSI report that includes the concatenated CSI element, and cause the CSI report to be transmitted to a base station within a single slot. Other embodiments may be described and/or claimed.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/479,195, filed Jul. 18, 2019, entitled “CHANNEL STATEINFORMATION CONCATENATION AND ANTENNA PORT MEASUREMENT,” now allowed,which is a U.S. National Phase of International Application No.PCT/US2018/037351, filed Jun. 13, 2018, which claims priority to U.S.Provisional Patent Application No. 62/520,846, filed Jun. 16, 2017,entitled “SINGLE SLOT CHANNEL STATE INFORMATION (CSI) REPORTING” andU.S. Provisional Patent Application No. 62/531,571, filed Jul. 12, 2017,entitled “ANTENNA PORT CONFIGURATION FOR NEW RADIO COMMUNICATIONSYSTEMS,” all of which are herein incorporated by reference in theirentireties.

TECHNICAL FIELD

The present disclosure relates to the field of wireless network systems.More particularly, the present disclosure relates to the measurement andreporting of channel state information within wireless network systems.

BACKGROUND

The background description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Unless otherwiseindicated herein, the materials described in this section are not priorart to the claims in this application and are not admitted to be priorart by inclusion in this section.

In legacy wireless systems, base stations supported user equipmenthaving similar capabilities. The user equipment would measure channelstate information (CSI) for all the antenna ports of a base station togenerate a CSI report. Further, the user equipment would report portionsof the CSI in different slots of a frame structure. As the number ofantenna ports supported by the base stations have increased, efficiencyin CSI reporting may be available.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be readily understood by the following detaileddescription in conjunction with the accompanying drawings. To facilitatethis description, like reference numerals designate like structuralelements. Embodiments are illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings.

FIG. 1 illustrates a table showing example channel state information(CSI) content, according to various embodiments.

FIG. 2 illustrates an example of CSI concatenation approach, accordingto various embodiments.

FIG. 3 illustrates an example table showing example rate indication(RI)-precoding matrix indication (PMI) indices, according to variousembodiments.

FIG. 4 illustrates another example of CSI concatenation approach,according to various embodiments.

FIG. 5 illustrates another example of CSI concatenation approach,according to various embodiments.

FIG. 6 illustrates another example of CSI concatenation approach,according to various embodiments.

FIG. 7 illustrates a CSI report procedure, according to variousembodiments.

FIG. 8 illustrates a CSI determination procedure, according to variousembodiments.

FIG. 9 illustrates an example antenna port arrangement, according tovarious embodiments.

FIG. 10 illustrates another example antenna port arrangement, accordingto various embodiments.

FIG. 11 illustrates another example antenna port arrangement, accordingto various embodiments.

FIG. 12 illustrates an example procedure of CSI calculation, accordingto various embodiments.

FIG. 13 illustrates a subset configuration procedure, according tovarious embodiments.

FIG. 14 illustrates an architecture of a system of a network inaccordance with some embodiments.

FIG. 15 illustrates example components of a device in accordance withsome embodiments.

FIG. 16 illustrates example interfaces of baseband circuitry inaccordance with some embodiments.

FIG. 17 is an illustration of a control plane protocol stack inaccordance with some embodiments.

FIG. 18 is an illustration of a user plane protocol stack in accordancewith some embodiments.

FIG. 19 illustrates components of a core network in accordance with someembodiments.

FIG. 20 is a block diagram illustrating components, according to someexample embodiments, able to read instructions from a machine-readableor computer-readable medium (e.g., a non-transitory machine-readablestorage medium) and perform any one or more of the methodologiesdiscussed herein.

DETAILED DESCRIPTION

Herein described are apparatuses, systems, and methods for measurementand reporting of channel state information within wireless networksystems. In embodiments, an apparatus for a user equipment (UE) mayinclude memory to store a rank indicator (RI), a precoding matrix index(PMI), and a channel quality indicator (CQI) of channel stateinformation (CSI) for the UE. The apparatus may further includecircuitry to concatenate the RI, the PMI, and the CQI to produce aconcatenated CSI element, generate a CSI report that includes theconcatenated CSI element, and cause the CSI report to be transmitted toa base station within a single slot.

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof wherein like numeralsdesignate like parts throughout, and in which is shown by way ofillustration embodiments that may be practiced. It is to be understoodthat other embodiments may be utilized and structural or logical changesmay be made without departing from the scope of the present disclosure.Therefore, the following detailed description is not to be taken in alimiting sense, and the scope of embodiments is defined by the appendedclaims and their equivalents.

Aspects of the disclosure are disclosed in the accompanying description.Alternate embodiments of the present disclosure and their equivalentsmay be devised without parting from the spirit or scope of the presentdisclosure. It should be noted that like elements disclosed below areindicated by like reference numbers in the drawings.

Various operations may be described as multiple discrete actions oroperations in turn, in a manner that is most helpful in understandingthe claimed subject matter. However, the order of description should notbe construed as to imply that these operations are necessarily orderdependent. In particular, these operations may not be performed in theorder of presentation. Operations described may be performed in adifferent order than the described embodiment. Various additionaloperations may be performed and/or described operations may be omittedin additional embodiments.

For the purposes of the present disclosure, the phrase “A and/or B”means (A), (B), or (A and B). For the purposes of the presentdisclosure, the phrase “A, B, and/or C” means (A), (B), (C), (A and B),(A and C), (B and C), or (A, B and C).

The description may use the phrases “in an embodiment,” or “inembodiments,” which may each refer to one or more of the same ordifferent embodiments. Furthermore, the terms “comprising,” “including,”“having,” and the like, as used with respect to embodiments of thepresent disclosure, are synonymous.

As used herein, the term “circuitry” may refer to, be part of, orinclude an Application Specific Integrated Circuit (ASIC), an electroniccircuit, a processor (shared, dedicated, or group) and/or memory(shared, dedicated, or group) that execute one or more software orfirmware programs, a combinational logic circuit, and/or other suitablecomponents that provide the described functionality.

FIG. 1 illustrates a table 100 showing example channel state information(CSI) content, according to various embodiments. In particular, thetable 100 illustrates CSI content and content size for an example newradio (NR) type I single panel codebook.

The table 100 indicates CSI content dependent on rank (or rank indicator(RI)) for the CSI, as indicated by the rank column 102. The rank mayindicate how many multiple-input, multiple-output (MIMO) layers arepreferred for downlink transmission for a user equipment (UE). The sizeof the elements within the CSI may be dependent, at least partially, onthe rank.

The table 100 further indicates a configuration of a codebook associatedwith the UE, as indicated by configuration column 104. For example, theconfiguration for the codebook may be dependent on a special codebookconfiguration element, represented by L in the illustrated embodiment,and/or a number of antenna elements or antenna ports, as represented bya number of antenna elements N₁ in the horizontal dimension of anantenna array and a number of antenna elements N₂ in the verticaldimension of the antenna array. The size of the elements within the CSImay be dependent, at least partially, on the configuration of thecodebook.

The table 100 further indicates a number of bits that indicates a subsetof beams to be utilized for transmissions, as represented by i₁ andindicated by i₁ column 106. The number of bits that indicate a subset ofbeams may vary based on the rank for the CSI, the configuration of thecodebook, or some combination thereof. In particular, an equation fordetermining the number of bits may differ, as indicated in the table100, based on the rank for the CSI, the configuration of the codebook,or some combination thereof. Further, the calculation of the number ofthe bits may depend on the number of antenna ports, as represented by N₁and N₂ in the illustrated embodiment, and/or a density of beams emittedfrom the antenna array, as represented by a density O₁ in the horizontaldimension of the antenna array and a density O₂ in the verticaldimension of the antenna array.

The table 100 further indicates a number of bits that indicates an exactbeam to be utilized for transmissions, as represented by i₂ andindicated by i₂ column 108. The number of bits that indicate the exactbeam may vary based on the rank for the CSI, the configuration of thecodebook, or some combination thereof. The number of bits may be definedbased on a number of bits per sub band (SB), where the values indicatedin the i₂ column 108 indicate a number of bits utilized to indicate theexact beam per SB.

The table 100 further indicates example numbers of bits for elements ofthe CSI for a particular scenario, as represented by CSI bit size column110. In particular, the scenario may include an arrangement having 4SBs, 16 antenna elements (or antenna ports), 4 bits per SB, for achannel quality indicator (CQI), and 3 bits for a rank indicator (RI).In particular, the CSI bit size column 110 includes: an RI/precodermatrix indicator (PMI) subcolumn 112 that indicates a number of bitsutilized for providing RI and PMI within the CSI; a CQI subcolumn 114that indicates a number of bits utilized for providing CQI within theCSI; and a total subcolumn 116 that indicates a total number of bitsutilized for the CSI. As can be seen from the table 100, a total numberof bits utilized for the CSI may vary based on the rank, the codebookconfiguration, or some combination thereof

A base station (such as a NodeB (NB), an evolved NodeB (eNB), a nextgeneration NodeB (gNB), RAN Node XS11 (FIG. 14), and/or RAN Node XS12(FIG. 14)) may not know the total number of bits utilized for the CSIuntil a CSI report is received at the base station. For example, thebase station may determine the total number of bits utilized for the CSIfrom the received CSI report. Further, NR may support single codewordfor CSI up to rank of 4 and two codewords for CSI for ranks greater than4, which may cause double CQI size and further variation in the totalnumber of bits utilized for the CSI.

Further, a format of a physical uplink control channel (PUCCH)transmission carrying a CSI report and/or an amount of resources for aselected PUCCH format carrying the CSI report may vary somewhatdynamically based on the RI. For example, the number of physicalresource blocks (PRBs) for CSI transmission may change depending on theRI and/or the CSI feedback mode. In particular, the number of PRBs usedfor the CSI report may change dynamically with changes (increase ordecrease) in CSI content size. The resource to be used for transmissionof the CSI report may be configured via higher layers or may be definedin technical specifications related to 5G.

In some embodiments, the PUCCH format and amount of resources utilizedfor transmission of the CSI report may be configured to support amaximum CSI content size. In these embodiments, when the CSI contentsize is smaller than the maximum CSI content size, filler bits may beadded to the CSI in the CSI report to transform the CSI content size inthe CSI report to the maximum CSI content size. For example, bits havinga value of 0 may be added to the CSI to increase the CSI content size tothe maximum CSI content size for a CSI report.

In instances where both the base station and the UE are aware of the CSIelements included a CSI report, the PUCCH format and/or an amount of aresource for transmission of the CSI report may change accordingly. Inparticular, both the base station and the UE may be configured to beaware of the PUCCH format and the resources utilized for transmission ofthe CSI report, such that the UE may format the CSI report in a definedformat and transmit the CSI report on defined resources, and the basestation may monitor the defined resources for the CSI report anddetermine the information included in the CSI report based on thedefined format. This may provide for more efficient reporting of the CSIinformation than embodiments where either the base station or the UE areunware of the PUCCH format and/or amount of resources utilized for thetransmission of the CSI report.

In case of single slot reporting, the size of CSI contents can depend onthe RI, which may not be known at the base station prior to the report.Furthermore, NR may support single codeword up to rank 4 and twocodewords otherwise, which may cause double CQI size for above rank 4.In order to support various PUCCH sizes, which can change somewhatdynamically depending on the reported RI, the format of the PUCCHcarrying the CSI report and the amount of the resource used for theselected PUCCH format, e.g., number of physical resource blocks, canchange depending on the RI as well as the CSI feedback mode. Morespecifically, the number of used physical resource blocks (PRBs) maychange dynamically with an increase in CSI contents size. Which resourceto use as the amount of resource changes can be configured via higherlayers or predefined in the specification. In another approach, thePUCCH format and the amount of the resource can be configured and usedin the way to support the case of the maximum CSI contents size. Incases that both the base station and the UE are aware of whatcombinations of CSI fields are included in the CSI report, the PUCCHformat and the amount of the resource can change accordingly.

FIG. 2 illustrates an example of CSI concatenation approach 200,according to various embodiments. The CSI concatenation approach 200 maybe performed by a UE for generation of a CSI report to be transmitted toa base station. In some embodiments, baseband circuitry (such asbaseband circuitry XT04 (FIG. 15)) of the UE may perform the CSIconcatenation approach 200. The UE may perform the CSI concatenationapproach 200 in response to receiving and/or identifying a channel stateinformation reference signal (CSI-RS) from the base station.

For the CSI concatenation approach 200, the UE may concatenate an RI, aPMI, and a CQI (collectively, “CSI elements”) of CSI for the UE prior tocoding of the CSI for transmission within a CSI report. For example, theUE may determine values for the RI, the PMI, and the CQI via measuringof a channel based on the CSI-RS received from the base station.

Prior to concatenation, the UE may determine whether a payload size ofthe CSI elements is a maximum payload size. In particular, the UE maycompare bit sizes of the RI, the PMI, and the CQI with maximumpredefined bit sizes for RI, PMI, and CQI. If the UE determines that theRI, the PMI, and the CQI are the maximum predefined bit sizes, the UEmay proceed to concatenation. If the UE determines that any of the RI,the PMI, and the CQI are smaller than the maximum predefined bit sizes,the UE may add filler bits to the RI, the PMI, and/or the CQI to havethe RI, the PMI, and the CQI be the maximum predefined bit sizes priorto concatenation.

The UE may concatenate the RI, the PMI, and the CQI to produce aconcatenated CSI element 202. For example, the bits for the RI arerepresented by o₀ ^(RI), o₁ ^(RI) . . . , o_(o) _(RI) ⁻¹ ^(RI) in theillustrated embodiment, with the maximum bit size of RI o^(RI). Thetable 100 shows o^(RI) equal to 3. Further, the bits for PMI arerepresented by o₀ ^(PMI), o₁ ^(PMI) . . . , o_(o) _(PMI) ⁻¹ ^(PMI) inthe illustrated embodiment, with the maximum bit size of PMI o^(PMI).The table 100 shows o^(PMI) equal to 16 for L=1 and o^(PMI) f equal to22 for L=4. Further, the bits for CQI are represented by o₀ ^(CQI), o₁^(CQI) . . . , o₀ _(CQI) ⁻¹ ^(CQI) in the illustrated embodiment, withthe maximum bit size of CQI o^(CQI). The table 100 shows o^(CQI) equalto 32.

The UE may then encode the concatenated CSI element 202. For example,the UE may perform a channel coding procedure 204 with the concatenatedCSI element 202. The UE may encode the concatenated CSI element 202 bypolar code, Reed-Muller code, or some other code utilized for CSIreporting. The channel coding of the concatenated CSI element 202 mayresult in encoded CSI element 206. The encoded CSI element 206 mayinclude jointly encoded bits q₀ ^(RI-PMI-CQI), q₁ ^(RI-PMI-CQI) . . . ,q_(o) _(RI-PMI-CQI) ⁻¹ ^(RI-PMI-CQI).

In some embodiments, the UE may limit the RI to a certain number. Forexample, the range of possible RI may be limited to 4. In theseembodiments, the size of the CQI may be fixed to 16 (assuming 4 SBs).Accordingly, a size variation corresponding to different ranks may besmaller.

FIG. 3 illustrates an example table 300 showing example rate indication(RI)-precoding matrix indication (PMI) indices, according to variousembodiments. In particular, a UE may perform joint RI and PMI indexing,resulting in RI-PMI indices in some embodiments. For example, basebandcircuitry (such as baseband circuitry XT04 (FIG. 15)) of the UE mayperform the joint RI and PMI indexing in some embodiments. Each of theRI-PMI values for the RI-PMI indices may correspond to particularcombinations of RI and PMI values.

The table 300 includes an RI-PMI index column 302, an RI column 304, anda PMI column 306. The RI-PMI index value in a row may correspond to anRI and a PMI within the same row. For example, the RI-PMI index value ina first row 308 may correspond to the RI in the first row 308 and thePMI in the first row 308. A size of the RI-PMI index may be set to afixed value, which may a maximum possible size of the RI-PMI index.

FIG. 4 illustrates another example of CSI concatenation approach 400,according to various embodiments. In particular, the CSI concatenationapproach 400 may utilize the RI-PMI indices, as described in regards totable 300 (FIG. 3). The CSI concatenation approach 400 may be performedby a UE for generation of a CSI report to be transmitted to a basestation. For example, baseband circuitry (such as baseband circuitryXT04 (FIG. 15)) of the UE may perform the CSI concatenation approach 400in some embodiments. The UE may perform the CSI concatenation approach400 in response to receiving and/or identifying a CSI-RS from the basestation.

The UE may determine values for the RI, the PMI, and the CQI viameasuring of a channel based on the CSI-RS received from the basestation. The UE may perform the RI and PMI indexing described inrelation to FIG. 3 to generate RI-PMI index values based on thedetermined RI and PMI. The UE may then concatenate the RI-PMI indexvalues with the CQI.

Prior to concatenation, the UE may determine whether a payload size ofthe RI-PMI index values and/or the CQI are maximum payload sizes,respectively. In particular, the UE may compare bit sizes of the RI-PMIindex values within maximum predefined bit sizes for the RI-PMI index.Further, the UE may compare bit sizes of the CQI with maximum predefinedbit sizes for the CQI. If the UE determines that the RI index values andthe CQI are the maximum predefined bit sizes, the UE may proceed toconcatenation. If the UE determines that either of the RI-PMI indexvalues or the CQI are smaller than the maximum predefined bit sizes, theUE may add filler bits to the RI-PMI index values and/or the CQI to havethe RI-PMI index values and the CQI be the maximum predefined bit sizesprior to concatenation.

The UE may concatenate the RI-PMI index values and the CQI to produce aconcatenated CSI element 402. For example, the bits for the RI-PMI indexvalues are represented by o₀ ^(RI-PMI), o₁ ^(RI-PMI) . . . , o_(o)_(RI-PMI) ⁻¹ ^(RI-PMI) in the illustrated embodiment, with the maximumbit size of CQI o^(CQI). The table 100 shows o^(CQI) equal to 32.

The UE may then encode the concatenated CSI element 402. For example,the UE may perform a channel coding procedure 404 with the concatenatedCSI element 402. The UE may encode the concatenated CSI element 402 bypolar code, Reed-Muller code, or some other code utilized for CSIreporting. The channel coding of the concatenated CSI element 402 mayresult in encoded CSI element 406. The encoded CSI element 406 mayinclude jointly encoded bits q₀ ^(RI-PMI-CQI), q₁ ^(RI-PMI-CQI) . . . ,q_(o) _(RI-PMI-CQI) ⁻¹ ^(RI-PMI-CQI).

FIG. 5 illustrates another example of CSI concatenation approach 500,according to various embodiments. In particular, the CSI concatenationapproach 500 may utilize the RI-PMI indices, as described in regards totable 300 (FIG. 3). The CSI concatenation approach 500 may be performedby a UE for generation of a CSI report to be transmitted to a basestation. For example, baseband circuitry (such as baseband circuitryXT04 (FIG. 15)) may perform the CSI concatenation approach 500. The UEmay perform the CSI concatenation approach 500 in response to receivingand/or identifying a CSI-RS from the base station.

The UE may determine values for the RI, the PMI, and the CQI viameasuring of a channel based on the CSI-RS received from the basestation. The UE may perform the RI and PMI indexing described inrelation to FIG. 3 to generate RI-PMI index values based on thedetermined RI and PMI.

In CSI concatenation approach 500, the UE may encode the RI-PMI indexvalues 502 and the CQI 508 prior to concatenation of the RI-PMI indexvalues 502 with the CQI 508. For example, the bits for the RI-PMI indexvalues 502 are represented by o₀ ^(RI-PMI), o₁ ^(RI-PMI) . . . , o_(o)_(RI-PMI) ⁻¹ ^(RI-PMI) in the illustrated embodiment, with the maximumbit size of RI-PMI index o^(RI-PMI). The UE may perform a channel codingprocedure 504 with the RI-PMI index values 502. The UE may encode theRI-PMI index values 502 by polar code, Reed-Muller code, or some othercode utilized for CSI reporting. The channel coding of the RI-PMI indexvalues 502 may result in encoded RI-PMI index values 506. The encodedRI-PMI index values 506 may include encoded bits q₀ ^(RI-PMI), q₁^(RI-PMI) . . . , q_(Q) _(RI-PMI) ⁻¹ ^(RI-PMI).

Further, the bits for CQI 508 are represented by o₀ ^(CQI), o₁ ^(CQI) .. . , o_(o) _(CQI) ⁻¹ ^(CQI) in the illustrated embodiment, with themaximum bit size of CQI o^(CQI). In embodiments where the RI is equal toor smaller than 4, the o^(CQI) may be equal to 16. In embodiments wherethe RI is equal to or greater than 4, the o^(CQI) may be equal to 32.The UE may perform a channel coding procedure 510 with CQI 508. The UEmay encode the CQI 508 by polar code, Reed-Muller code, or some othercode utilized for CSI. In some embodiments, the UE may encode the CQI508 by a different code format than the RI-PMI index values 502. Forexample, the RI-PMI index values 502 may be encoded by Reed-Muller code,whereas the CQI 508 may be encoded by polar code. The channel coding ofthe CQI 508 may result in encoded CQI 512. The encoded CQI 512 mayinclude the encoded bits q₀ ^(CQI), q₁ ^(CQI) . . . , q_(Q) _(CQI) ⁻¹^(CQI). In some embodiments, the coding rate for the RI-PMI index values502 may be lower than a coding rate for the CQI 508.

The UE may then perform a multiplexing and interleaving operation 514with the encoded RI-PMI index values 506 and the encoded CQI 512. Forexample, the two sequences of encoded bits corresponding to the encodedRI-PMI index values 506 and the encoded CQI 512, respectively, may bemultiplexed and interleaved before being mapped to resources fortransmission. The multiplexing and interleaving of the encoded RI-PMIindex values 506 and the encoded CQI 512 may produce a concatenated CSIelement. In some embodiments, the baseband circuitry of the UE may causeradio frequency (RF) circuitry (such as RF circuitry XT06 (FIG. 15)) ofthe UE to perform the multiplexing and interleaving. In otherembodiments, the baseband circuitry of the UE may perform themultiplexing and interleaving. In some embodiments, each encoded bit ofthe encoded RI-PMI index values 506 and the encoded CQI 512 may bemapped to different PUCCH formats. For example, each encoded bit of theencoded RI-PMI index values 506 may be mapped in a different PUCCHformat from the encoded CQI 512. In some embodiments, each encoded bitof the encoded RI-PMI index values 506 and the encoded CQI 512 may bemapped to different PUCCH symbols. For example, each encoded bit of theencoded RI-PMI index values 506 may be mapped to a different PUCCHsymbol from the encoded CQI 512.

FIG. 6 illustrates another example of CSI concatenation approach 600,according to various embodiments. In particular, the CSI concatenationapproach 600 may concatenate the PMI and CQI prior to encoding andfurther concatenate with the RI after encoding. The CSI concatenationapproach 600 may be performed by a UE for generation of a CSI report tobe transmitted to a base station. For example, baseband circuitry (suchas baseband circuitry XT04 (FIG. 15)) may perform the CSI concatenationapproach 600. The UE may perform the CSI concatenation approach 600 inresponse to receiving and/or identifying a CSI-RS from the base station.

The UE may determine values for the RI, the PMI, and the CQI viameasuring of a channel based on the CSI-RS received from the basestation. In CSI concatenation approach 600, the UE may concatenate thePMI and the CQI prior to encoding to produce concatenated PMI-CQI 602.The bits for the PMI are represented by o₀ ^(PMI), o₁ ^(PMI) . . . ,o_(o) _(PMI) ⁻¹ ^(PMI) within the concatenated PMI-CQI 602. Further, thebits for CQI are represented by o₀ ^(CQI), o₁ ^(CQI) . . . , o_(o)_(CQI) ⁻¹ ^(CQI). The bit size of the PMI and the CQI may be determinedbased on the RI.

The UE may perform a channel coding procedure 604 with the concatenatedPMI-CQI 602. For example, the UE may encode the concatenated PMI-CQI 602by polar code, Reed-Muller code, or some other code utilized for CSIreporting. The channel coding of the concatenated PMI-CQI 602 may resultin encoded PMI-CQI 606. The encoded PMI-CQI 606 may include bits q₀^(PMI-CQI), q₁ ^(PMI-CQI) . . . , q_(Q) _(PMI-CQI) ⁻¹ ^(PMI-CQI).

Further, the bits for RI 608 are represented by o₀ ^(RI), o₁ ^(RI) . . ., o_(o) _(RI) ⁻¹ ^(RI) in the illustrated embodiment, with the maximumbit size of RI o^(RI). The UE may perform a channel coding procedure 610with RI 608. The UE may encode the RI 608 by polar code, Reed-Mullercode, or some other code utilized for CSI. In some embodiments, the UEmay encode the RI 608 by a different code format than the concatenatedPMI-CQI 602. For example, the RI 608 may be encoded by Reed-Muller code,whereas the concatenated PMI-CQI 602 may be encoded by polar code. Thechannel coding of the RI 608 may result in encoded RI 612. The encodedRI 612 may include the encoded bits q₀ ^(RI), q₁ ^(RI) . . . , q_(o)_(RI) ⁻¹ ^(RI). In some embodiments, the coding rate for the RI 608 maybe lower than a coding rate for the concatenated PMI-CQI 602.

The UE may then perform a multiplexing and interleaving operation 614with the encoded RI 612 and the encoded PMI-CQI 606 in some embodiments.For example, the two sequences of encoded bits corresponding to theencoded RI 612 and the encoded PMI-CQI 606, respectively, may bemultiplexed and interleaved before being mapped to resources fortransmission. The multiplexing and interleaving of the encoded RI 612and the PMI-CQI 606 may produce a concatenated CSI element. In someembodiments, the baseband circuitry of the UE may cause radio frequency(RF) circuitry (such as RF circuitry XT06 (FIG. 15)) of the UE toperform the multiplexing and interleaving. In other embodiments, thebaseband circuitry of the UE may perform the multiplexing andinterleaving. In some embodiments, each encoded bit of the encodedPMI-CQI 606 and the encoded RI 612 may be mapped to different PUCCHformats. For example, each encoded bit of the encoded PMI-CQI 606 may bemapped in a different PUCCH format from the encoded RI 612. In someembodiments, each encoded bit of the encoded PMI-CQI 606 and the encodedRI 612 may be mapped to different PUCCH symbols. For example, eachencoded bit of the encoded PMI-CQI 606 may be mapped to a differentPUCCH symbol from the encoded RI 612.

FIG. 7 illustrates a CSI report procedure 700, according to variousembodiments. The CSI report procedure 700 may be performed by a UE, suchas the UE XS01 (FIG. 14) and the UE XS02 (FIG. 14).

In stage 702, the UE may identify a CSI-RS received from a base station.In response to identifying the CSI-RS, the procedure may proceed tostage 704.

In stage 704, the UE may determine CSI via channel estimation. Inparticular, the UE may measure channel properties associated with acommunication link between the UE and the base station. For example, theUE may determine CSI for the communication link that includes an RI, aPMI, and a CQI.

In stage 706, the UE may implement a CSI concatenation approach with theRI, the

PMI, and the CQI. In particular, the UE may implement one of the CSIconcatenation approach 200 (FIG. 2), the CSI concatenation approach 400(FIG. 4), the CSI concatenation approach 500 (FIG. 5), or the CSIconcatenation approach 600 (FIG. 6). The implementation of the CSIconcatenation approach may produce a concatenated CSI element forinclusion within a CSI report.

In stage 708, the UE may generate a CSI report for transmission to thebase station. The CSI report may include the concatenated CSI elementproduced in stage 706.

In stage 710, the UE may map the CSI report to a resource or resourcesfor transmission to the base station. The UE may map the CSI report to asingle slot for transmission to the base station. For example, the UEmay map the CSI report to a single slot of a PUCCH for reporting. Inembodiments, a portion of the CSI report may be mapped to a differentPUCCH symbol than another portion of the CSI report, as described inrelation to the CSI concatenation approach 500 or the CSI concatenationapproach 600. Further, a portion of the CSI report may be mapped to adifferent PUCCH format than another portion of the CSI report, asdescribed in relation to the CSI concatenation approach 500 or the CSIconcatenation approach 600.

In stage 712, the UE may transmit the CSI report to the base station onthe mapped resource or resources.

FIG. 8 illustrates a CSI determination procedure 800, according tovarious embodiments. The CSI determination procedure 800 may beperformed by a base station, such as RAN Node XS11 (FIG. 14) and RANNode XS12 (FIG. 14).

In stage 802, the base station may identify a transmission received froma UE. The transmission may include CSI, or some portion thereof. In someembodiments, the transmission may comprise a CSI report. The CSI reportmay include an RI, a PMI, and a CQI determined by the UE based on aCSI-RS transmitted by the base station.

In other embodiments, the transmission may comprise a demodulationreference signal (DMRS). A sequence of the DMRS may be configured basedon an RI associated with CSI for the UE. In particular, the UE may havedetermined the RI based on a CSI-RS transmitted by the base station andconfigured the sequence of the DMRS based on the RI.

In stage 804, the base station may determine the channel stateinformation. In embodiments where the transmission comprises a CSIreport, the base station may assume certain bit sizes of the RI, thePMI, and the CQI. For example, the base station may assume the bit sizesof the RI, the PMI, and the CQI correspond to one of the rowsillustrated in the table 100 (FIG. 1). The base station may assume bitsizes to correspond to a certain rank, such as a rank of 1. In someembodiments, the possible RI values may be limited to reduce thepotential bit sizes of the RI, the PMI, and/or the CQI. The base stationmay then decode the CSI report based on the assumed bit sizes todetermine values of the RI, the PMI, and the CQI.

In embodiments where the transmission comprises a DMRS, the base stationmay compare the sequence of the DMRS with a predefined DMRS sequenceassociated with a particular RI. In particular, the base station mayhave multiple predefined DMRS sequences stored in memory, where each ofthe predefined DMRS sequences correspond to a different RI value. Thebase station may select one of the multiple predefined DMRS sequences tocompare with the sequence of the received DMRS to determine whether thereceived DMRS is for an RI value that corresponds to the one of themultiple predefined DMRS sequences.

In stage 806, the base station may verify the validity of the CSI. Inembodiments where the transmission comprises a CSI report, the basestation may identify one or more cyclic redundancy check (CRC) bitsappended to the CSI report by the UE. The base station may compare thedetermined values of the RI, the PMI, and the CQI with the CRC bits todetermine if the CSI has been correctly decoded. In particular, the basestation may compare the decoded bits for the RI, the PMI, and the CQIwith the CRC bits to determine if the assumed bit sizes of the RI, thePMI, and the CQI utilized for determining the CSI were the correct bitsizes. In response to determining that the comparison of the decodedbits for the RI, the PMI, and the CQI with the CRC bits results in adetermination that the CSI is invalid (i.e., improper bit sizes of theRI, the PMI, and the CQI were assumed), the base station may repeatstage 804 and stage 806 with assumption of different bit sizes of theRI, the PMI, and the CQI until the comparison of the decoded bits forthe RI, the PMI, and the CQI with the CRC bits results in adetermination that the determined CSI is valid (i.e., proper bit sizesof the RI, the PMI, and the CQI were assumed).

In embodiments where the transmission comprises a DMRS, the base stationmay perform channel estimation based on the RI determined in stage 804to determine a signal to interference and noise ratio (SINR) associatedwith the one of the multiple predefined DMRS sequences utilized in stage804. The base station may further compare the sequence of the receivedDMRS with others of the multiple predefined DMRS sequences, anddetermine SINR for each of the others of the multiple predefined DMRSsequences. The base station may determine if the SINR for the RIdetermined in stage 804 is higher than the SINRs for each of the othersof the multiple predefined DMRS sequences. If the base stationdetermines that the SINR for the RI determined in stage 804 is lowerthan any of the SINRs for the others of the multiple predefined DMRSsequences, the base station may determine that the SINR for the RIdetermined in stage 804 is invalid. In response to determined that theSINR for the RI determined in stage 804 is invalid, the base station mayidentify the one of the others of the multiple predefined DMRS sequenceswith the highest SINR, and determine that the transmission is associatedwith the RI that corresponds to the predefined DMRS sequence with thehighest SINR.

In some embodiments where the transmission comprises a DMRS, the basestation may perform stage 804 for multiple, or all, of the predefinedDMRS sequences before proceeding to stage 806. For example, the basestation may compare the sequence of the received DMRS with each of thepredefined DMRS sequences. In these embodiments, the base station maydetermine SINRs for each of the predefined DMRS sequences to determineSINRs associated with RIs corresponding to each of the predefined DMRS.The base station may then select the highest SINR out of the determinedSINRs and determine that the valid RI associated with the received DMRSis the RI associated with the highest SINR.

In some embodiments, the CSI determination procedure 800 where thetransmission comprises a DMRS may be utilized in combination with theCSI concatenation approach 200 (FIG. 2), the CSI concatenation approach400 (FIG. 4), the CSI concatenation approach 500 (FIG. 5), the CSIconcatenation approach 600 (FIG. 6), the CSI determination procedure 800where the transmission comprises a CSI report, or some combinationthereof.

Further, in some embodiments, a maximum rank supported by the basestation and/or the UE may determine which of the CSI concatenationapproach 200, the CSI concatenation approach 400, the CSI concatenationapproach 500, the CSI concatenation approach 600, the CSI determinationprocedure 800 with the transmission comprising a DMRS, or the CSIdetermination procedure 800 with the transmission comprising a CSIreport is implemented. For example, a threshold rank, K, may bepredefined or configured by higher layer signaling. If the maximumsupported rank is greater than the threshold rank, one of the CSIconcatenation approach 200, the CSI concatenation approach 400, the CSIconcatenation approach 500, the CSI concatenation approach 600, or theCSI determination procedure 800 with the transmission comprising a CSIreport may be implemented. If the maximum supported rank is equal to orless than the threshold rank, the CSI determination procedure 800 withthe transmission comprising the DMRS may be implemented.

FIG. 9 illustrates an example antenna port arrangement 900, according tovarious embodiments. The antenna port arrangement 900, the antenna portarrangement 1000 (FIG. 10), the antenna port arrangement 1100 (FIG. 11),the procedure 1200 (FIG. 12) of CSI calculation, and the procedure 1300(FIG. 13) may relate to multiple-input, multiple-output (MIMO)communication systems, such as NR MIMO communication systems.

MIMO systems may rely on a plurality of transmission (Tx) and reception(Rx) antennas to provide spatial diversity, multiplexing, and arraygains in the downlink (DL) and uplink (UL) channels. In the DL, the Txcan improve the performance by using CSI about the DL channel observedby the Rx. The CSI can be obtained by the Tx from the Rx from estimationof the UL channel and by using channel reciprocity of the wirelesschannel, and/or from quantized feedback measured by the Rx.

The quantized form of CSI feedback may be more general and can be usedfor both Frequency Division Duplex (FDD) and Time Division Duplex (TDD)systems. The quantized CSI may include the PMI to assist beamforming orprecoding selection at the Tx antennas of the base station. The set ofpossible PMIs may be denoted as a codebook. For different possibledeployments of NR, the codebook may be designed to provide reasonableperformance in all possible serving directions of the total radiatedpower (TRP).

CSI-RS may be reference signals introduced to support channelmeasurement for CSI calculation. For NR, CSI-RS may support 2, 4, 8, 12,16, 24, and 32 antenna ports. The density of CSI-RS may be 1 resourceelement per physical resource block (PRB) pair per CSI-RS antenna port.CSI-RS can be located in every PRB or every second PRB or every thirdPRB. CSI-RS can be aperiodically, semi-persistently, or periodicallytransmitted. The minimum periodicity of CSI-RS transmission may be 5subframes or 5 slots. The parameters of CSI-RS may be configured to theuser equipment (UE) using higher layer signaling (e.g., radio resourcecontrol (RRC) signaling and the like) and CSI-RS presence can bedynamically indicated to the UE.

To reduce UE complexity, different UEs may be capable of CSI processingfor a different number of antenna ports. For example, UE complexity mayincrease as larger numbers of antenna ports are to be scanned by the UE.In particular, as the number of antenna ports are increased, a number ofbits for CSI reporting and/or a number of decoding vectors/matrices maybe increased, leading to higher UE complexity. Accordingly, some UEs maybe capable of supporting up to a certain number of antenna ports, suchas 8 or 16 antenna ports, while other UEs may support a greater numberof antenna ports. As a result, a base station may transmit multipleCSI-RS signals with a different number of antenna ports. For example,the base station may transmit one CSI-RS on all antenna ports of thebase station for more advanced UEs that support a greater amount ofantenna ports, and may transmit another CSI-RS on a portion of theantenna ports for less advanced UEs that support a lesser amount ofantenna ports. To reduce the overhead, a single CSI-RS signal can betransmitted by the base station and a UE capable of a smaller number ofantenna ports may use antenna port subset for channel measurements.

According to various embodiments, separate configurations of antennaports, N, for CSI-RS signal(s) and antenna ports, K, for codebook(s) maybe utilized, where N and K are numbers and N is greater than or equal toK (e.g., N>=K). According to various embodiments, a UE may use a subsetof K antenna ports for channel measurements using a codebook withantenna port K. For Physical Downlink Shared Channel (PDSCH) resourceelement (RE) mapping, the UE may assume a CSI-RS is transmitted on Nantenna ports.

The antenna port arrangement 900 illustrates an arrangement of anantenna array where a UE (such as UE XS01 (FIG. 14) and UE XS02 (FIG.14)) utilizes a subset of antenna ports for calculating CSI. Inparticular, a base station (such as RAN Node XS11 (FIG. 14) and RAN NodeXS12 (FIG. 14)) that communicates with the UE may include one or moreantenna elements 902. In the illustrated embodiment, the base stationincludes sixteen antenna elements 902, where each antenna element 902 isindicated by an ‘X’ in the antenna port arrangement 900. Further, eachantenna element 902 may provide two antenna ports, where each antennaport is indicated by a line in the ‘X’ of the antenna elements 902. Forexample, a first antenna element 902 a may provide a first antenna port904 and a second antenna port 906. The antenna elements 902 may supporta cross-polarized antenna configuration, where each antenna element 902provides two antenna ports having polarization slants of plus or minus45 degrees, respectively. The total number of antenna ports in theantenna port arrangement 900 illustrated is 32 antenna ports, where thetotal number of antenna ports provided by a base station may be referredto as ‘N’ antenna ports herein.

UEs may be capable of CSI processing for a maximum number of antennaports that is less than a total number of antenna ports provided by thebase station. In the illustrated embodiment, the UE may be capable ofCSI processing for a maximum of 16 antenna ports. Accordingly, the UEmay utilize a subset of the antenna ports provided by the base stationfor CSI processing to calculate CSI for the UE. In particular, the UEmay perform CSI calculation using a codebook having a number ofparameters equal to the number of antenna ports within the subset, wherethe UE may perform the CSI calculation on the subset. In the illustratedembodiment, the UE may utilize a subset of 16 antenna ports to calculateCSI for the UE.

A subset of antenna ports to be utilized by a UE may be predefined orconfigured by higher layer signaling. In the illustrated embodiment, theUE may be configured to utilize a first portion of a first half of theantenna ports (i.e., antenna ports 0, . . . , K/2−1, where K is thenumber of antenna ports within the subset) and a first portion of asecond half of the antenna ports (i.e., antenna ports N/2, . . .,N/2+K/2−1, wherein N is a total number of the antenna ports of theantenna port arrangement 900) to calculate CSI for the UE. The size ofthe portions may be equal to half of the number of antenna ports thatthe UE is capable of utilizing for CSI processing. In particular, the UEmay utilize a first portion 908 and a second portion 910 of the antennaports to calculate the CSI. For example, the UE may measure CSI-RStransmitted by the antenna ports within the first portion 908 and thesecond portion 910 to calculate the CSI for the UE.

In other embodiments, the UE may be configured to utilize a secondportion of the first half of the antenna ports and a second portion ofthe second half of the antenna ports to calculate the CSI for the UE. Inthese embodiments, the UE may utilize a third portion 912 and a fourthportion 914 of the antenna ports to calculate the CSI. For example, theUE may measure CSI-RS transmitted by the antenna ports within the thirdportion 912 and the fourth portion 914 to calculate the CSI for the UE.

FIG. 10 illustrates another example antenna port arrangement 1000,according to various embodiments. The antenna port arrangement 1000illustrates an arrangement of an antenna array where a UE (such as UEXS01 (FIG. 14) and UE XS02 (FIG. 14)) utilizes a subset of antenna portsfor calculating CSI. In particular, a base station (such as RAN NodeXS11 (FIG. 14) and RAN Node XS12 (FIG. 14)) that communicates with theUE may include one or more antenna elements 1002. In the illustratedembodiment, the base station includes sixteen antenna elements 1002,⋅where each antenna element 1002 is indicated by an ‘X’ in the antennaport arrangement 1000. Further, each antenna element 1002 may providetwo antenna ports, where each antenna port is indicated by a line in the‘X’ of the antenna elements 1002. For example, a first antenna element1002 a may provide a first antenna port 1004 and a second antenna port1006. The antenna elements 1002 may support a cross-polarized antennaconfiguration, where each antenna element 1002 provides two antennaports having polarization slants of plus or minus 45 degrees,respectively. The total number of antenna ports in the antenna portarrangement 1000 illustrated is 32 antenna ports, where the total numberof antenna ports provided by a base station may be referred to as ‘N’antenna ports herein.

In the illustrated embodiment, the base station may configure the UEwith which subset the UE is to utilize for calculating the CSI for theUE. In particular, the UE may be configured with parameter N1 1008 andparameter N2 1010. Parameter N1 1008 may indicate a number of theantenna elements 1002 in a first dimension of the antenna portarrangement 1000 and parameter N2 1010 may indicate a number of theantenna elements 1002 in a second dimension. In other embodiments, theparameter N1 1008 may indicate a number of antenna ports having acertain polarization in the first dimension and parameter N2 1010 mayindicate a number of antenna ports having the certain polarization inthe second dimension to be utilized for calculating the CSI.Accordingly, a total number of antenna ports in the antenna portarrangement 1000 may be defined as N=P*N1*N2, where N is the totalnumber of antenna ports and P is the number of polarizations of theantenna array. For the illustrated embodiment, the number of the antennaports may defined as N=2*4*4, where N is equal to 32.

The base station may further configure the UE with parameter K1 1012 andparameter K2 1014. Parameter K1 1012 may indicate a number of theantenna elements 1002 in the first dimension to define a subset of theantenna ports to be utilized by the UE for calculating the CSI andparameter K2 1014 may indicate a number of the antenna elements 1002 inthe second dimension to define a subset of the antenna ports to beutilized for calculating the CSI. In other embodiments, the parameter K11012 may indicate a number of antenna ports having a certainpolarization in the first dimension to be utilized by the UE forcalculating the CSI and parameter K2 1014 may indicate a number ofantenna ports having the certain polarization in the second dimension tobe utilized for calculating the CSI. Accordingly, the number of antennaports within the subset may be defined as K=P*K1*K2, where K is thenumber of antenna ports within the subset and P is the number ofpolarizations of the antenna array. For the illustrated embodiment, thenumber of antenna ports within the subset may be defined as K=2*2*2,where K is equal to 8.

For example, the base station may configure the UE with the parameter N11008 with a value of 4 and the parameter N2 1010 with a value of 4. Inparticular, the parameter N1 1008 indicates that there are 4 antennaelements 1002 in a vertical dimension of the antenna array and parameterN2 1010 indicates that there are 4 antenna elements 1002 in a horizontaldimension of the antenna array. Further, the base station may configurethe UE with the parameter K1 1012 with a value of 2 and the parameter K21014 with a value of 2. Accordingly, the base station may configure theUE with the subset 1016 of the antenna ports to be utilized forcalculating the CSI. Accordingly, the UE may perform channel estimationbased on CSI-RS transmitted on the antenna ports within the subset 1016and calculate the CSI based on the results of the channel estimation.

FIG. 11 illustrates another example antenna port arrangement 1100,according to various embodiments. The antenna port arrangement 1100illustrates an arrangement of an antenna array where a UE (such as UEXS01 (FIG. 14) and UE XS02 (FIG. 14)) utilizes a subset of antenna portsfor calculating CSI. In particular, a base station (such as RAN NodeXS11 (FIG. 14) and RAN Node XS12 (FIG. 14)) that communicates with theUE may include one or more antenna elements 1102. In the illustratedembodiment, the base station includes sixteen antenna elements 1102,where each antenna element 1102 is indicated by an ‘X’ in the antennaport arrangement 1100. Further, each antenna element 1102 may providetwo antenna ports, where each antenna port is indicated by a line in the‘X’ of the antenna elements 1102. For example, a first antenna element1102 a may provide a first antenna port 1104 and a second antenna port1106. The antenna elements 1102 may support a cross-polarized antennaconfiguration, where each antenna element 1102 provides two antennaports having polarization slants of plus or minus 45 degrees,respectively. The total number of antenna ports in the antenna portarrangement 1100 illustrated is 32 antenna ports, where the total numberof antenna ports provided by a base station may be referred to as ‘N’antenna ports herein.

In the illustrated embodiment, the base station may configure the UEwith which subset the UE is to utilize for calculating the CSI for theUE. In particular, the UE may be configured with parameter N1 1108 andparameter N2 1110. Parameter N1 1108 may indicate a number of theantenna elements 1102 in a first dimension of the antenna portarrangement 1100 and parameter N2 1110 may indicate a number of theantenna elements 1102 in a second dimension. In other embodiments, theparameter N1 1108 may indicate a number of antenna ports having acertain polarization in the first dimension and parameter N2 1110 mayindicate a number of antenna ports having the certain polarization inthe second dimension to be utilized for calculating the CSI.Accordingly, a total number of antenna ports in the antenna portarrangement 1100 may be defined as N=P*N1*N2, where N is the totalnumber of antenna ports and P is the number of polarizations of theantenna array. For the illustrated embodiment, the number of the antennaports may defined as N=2*4*4, where N is equal to 32.

The base station may further configure the UE with parameter K1 1112 andparameter K2 1114. Parameter K1 1112 may indicate a number of theantenna elements 1102 in the first dimension to define a subset of theantenna ports to be utilized by the UE for calculating the CSI andparameter K2 1114 may indicate a number of the antenna elements 1102 inthe second dimension to define a subset of the antenna ports to beutilized for calculating the CSI. In other embodiments, the parameter K11112 may indicate a number of antenna ports having a certainpolarization in the first dimension to be utilized by the UE forcalculating the CSI and parameter K2 1114 may indicate a number ofantenna ports having the certain polarization in the second dimension tobe utilized for calculating the CSI. Accordingly, the number of antennaports within the subset may be defined as K=P*K1*K2, where K is thenumber of antenna ports within the subset and P is the number ofpolarizations of the antenna array. For the illustrated embodiment, thenumber of antenna ports within the subset may be defined as K=2*4*1,where K is equal to 8.

For example, the base station may configure the UE with the parameter N11108 with a value of 4 and the parameter N2 1110 with a value of 4. Inparticular, the parameter N1 1108 indicates that there are 4 antennaelements 1102 in a vertical dimension of the antenna array and parameterN2 1110 indicates that there are 4 antenna elements 1102 in a horizontaldimension of the antenna array. Further, the base station may configurethe UE with the parameter K1 1112 with a value of 4 and the parameter K21114 with a value of 1. Accordingly, the base station may configure theUE with the subset 1116 of the antenna ports to be utilized forcalculating the CSI. Accordingly, the UE may perform channel estimationbased on CSI-RS transmitted on the antenna ports within the subset 1116and calculate the CSI based on the results of the channel estimation.

FIG. 12 illustrates an example procedure 1200 of CSI calculation,according to various embodiments. In particular, the procedure 1200 maybe performed by a UE, such as the UE XS01 and the UE XS02.

In stage 1202, the UE may receive a CSI-RS configuration including anumber of antenna ports N. In particular, the UE may be configured by abase station for a number of antenna ports N. In some embodiments, thebase station may indicate a number of antenna elements in each dimensionof an antenna array or a number of antenna ports of a certainpolarization in each dimension of the antenna array.

In stage 1204, the UE may identify an indication of a number of antennaport configuration K for a codebook. In particular, the UE may beconfigured by the base station with a subset of the antenna ports K tobe utilized by the UE for CSI calculation. In some embodiments, the basestation may indicate a number of elements in each dimension of theantenna array or a number of antenna ports of a certain polarization ineach dimension of the antenna array. In embodiments where the subset Kis predefined, stage 1204 may include retrieving an indication from amemory of the UE of the subset of antenna ports K to be utilized for CSIcalculation.

In stage 1206, the UE may measure the channel using the subset ofantenna ports K of the CSI-RS. In particular, the UE may perform channelestimation with the CSI-RS transmitted on the subset of the antennaports K.

In stage 1208, the UE may calculate CSI using the channel measurementson the subset of antenna ports K of CSI-RS with N antenna ports. Inparticular, the UE may calculate the CSI for the UE based on the channelmeasurements performed in stage 1206. Further, the UE may determine acodeword from the codebook based on the CSI. The UE may further transmita CSI report to the base station that indicates the calculated CSI. TheCSI report may include an indication of the codeword, where the basestation may utilize the codeword to determine precoding to betransmitted to the UE via a physical downlink shared channel (PDSCH).

In stage 1210, the UE may perform PDSCH reception assuming CSI-RStransmission using the subset of antenna ports K. For example, the UEmay identify data on the PDSCH, where the data is communicated on thesubset of antenna ports K by the base station. The data received may beprecoded based on the codeword transmitted to the base station by the UEin the CSI report.

FIG. 13 illustrates a subset configuration procedure 1300, according tovarious embodiments. In particular, the subset configuration procedure1300 may be performed by a base station, such as the RAN Node XS11 (FIG.14) and the RAN Node XS12 (FIG. 14).

In stage 1302, the base station may generate a CSI-RS configuration. Forexample, the base station may generate the CSI-RS configuration for a UEand may configure the UE with the CSI-RS configuration. The CSI-RS mayinclude an indication of a number of antenna ports N provided by thebase station. In particular, the antenna ports may be provided by anantenna array of the base station.

In stage 1304, the base station may generate a message for transmissionto the UE. The message may include a subset configuration forconfiguring the UE with a subset of the antenna ports K to be utilizedby the UE for calculating CSI. In particular, the message may include anindication of the subset of the antenna ports K to be utilized by the UEfor calculating the CSI. The indication of the subset may include anindication of a number of antenna ports in a first dimension and anumber of antenna ports in a second dimension that define the subset K.In some embodiments, the indication of the subset may include anindication of a number of antenna elements in a first dimension and anumber of antenna elements in a second dimension that defined the subsetK. The base station may utilize the message to configure the UE with thesubset.

In stage 1306, the base station may generate a CSI-RS. The base stationmay transmit the CSI-RS to the UE on the subset of the antenna ports K.The UE may utilize the CSI-RS for calculating the CSI.

In stage 1308, the base station may identify CSI received from the UE.The CSI may include a PMI, which may be identified by the base station.The base station may determine precoding to be performed for the UEbased on the PMI.

In stage 1310, the base station may apply the precoding to transmissionsto be provided to the UE by the base station. For example, the basestation may apply the precoding determined in stage 1308 to data to betransmitted to the UE via the PDSCH. The precoded data may betransmitted by the base station on the subset of antenna ports K to theUE.

FIG. 14 illustrates an architecture of a system XS00 of a network inaccordance with some embodiments. The system XS00 is shown to include auser equipment (UE) XS01 and a UE XS02. The UEs XS01 and XS02 areillustrated as smartphones (e.g., handheld touchscreen mobile computingdevices connectable to one or more cellular networks), but may alsocomprise any mobile or non-mobile computing device, such as PersonalData Assistants (PDAs), pagers, laptop computers, desktop computers,wireless handsets, or any computing device including a wirelesscommunications interface.

In some embodiments, any of the UEs XS01 and XS02 can comprise anInternet of Things (IoT) UE, which can comprise a network access layerdesigned for low-power IoT applications utilizing short-lived UEconnections. An IoT UE can utilize technologies such asmachine-to-machine (M2M) or machine-type communications (MTC) forexchanging data with an MTC server or device via a public land mobilenetwork (PLMN), Proximity-Based Service (ProSe) or device-to-device(D2D) communication, sensor networks, or IoT networks. The M2M or MTCexchange of data may be a machine-initiated exchange of data. An IoTnetwork describes interconnecting IoT UEs, which may include uniquelyidentifiable embedded computing devices (within the Internetinfrastructure), with short-lived connections. The IoT UEs may executebackground applications (e.g., keep-alive messages, status updates,etc.) to facilitate the connections of the IoT network.

The UEs XS01 and XS02 may be configured to connect, e.g.,communicatively couple, with a radio access network (RAN) XS10—the RANXS10 may be, for example, an Evolved Universal Mobile TelecommunicationsSystem (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN(NG RAN), or some other type of RAN. The UEs XS01 and XS02 utilizeconnections XS03 and XS04, respectively, each of which comprises aphysical communications interface or layer (discussed in further detailbelow); in this example, the connections XS03 and XS04 are illustratedas an air interface to enable communicative coupling, and can beconsistent with cellular communications protocols, such as a GlobalSystem for Mobile Communications (GSM) protocol, a code-divisionmultiple access (CDMA) network protocol, a Push-to-Talk (PTT) protocol,a PTT over Cellular (POC) protocol, a Universal MobileTelecommunications System (UMTS) protocol, a 3GPP Long Term Evolution(LTE) protocol, a fifth generation (5G) protocol, a New Radio (NR)protocol, and the like.

In this embodiment, the UEs XS01 and XS02 may further directly exchangecommunication data via a ProSe interface XS05. The ProSe interface XS05may alternatively be referred to as a sidelink interface comprising oneor more logical channels, including but not limited to a PhysicalSidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel(PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a PhysicalSidelink Broadcast Channel (PSBCH).

The UE XS02 is shown to be configured to access an access point (AP)XS06 via connection XS07. The connection XS07 can comprise a localwireless connection, such as a connection consistent with any IEEE802.11 protocol, wherein the AP XS06 would comprise a wireless fidelity(WiFi®) router. In this example, the AP XS06 is shown to be connected tothe Internet without connecting to the core network of the wirelesssystem (described in further detail below).

The RAN XS10 can include one or more access nodes that enable theconnections XS03 and XS04. These access nodes (ANs) can be referred toas base stations (BSs), NodeBs, evolved NodeBs (eNBs), next GenerationNodeBs (gNB), RAN nodes, and so forth, and can comprise ground stations(e.g., terrestrial access points) or satellite stations providingcoverage within a geographic area (e.g., a cell). The RAN XSIO mayinclude one or more RAN nodes for providing macrocells, e.g., macro RANnode XS11, and one or more RAN nodes for providing femtocells orpicocells (e.g., cells having smaller coverage areas, smaller usercapacity, or higher bandwidth compared to macrocells), e.g., low power(LP) RAN node XS12.

Any of the RAN nodes XS11 and XS12 can terminate the air interfaceprotocol and can be the first point of contact for the UEs XS01 andXS02. In some embodiments, any of the RAN nodes XS11 and XS12 canfulfill various logical functions for the RAN XS10 including, but notlimited to, radio network controller (RNC) functions such as radiobearer management, uplink and downlink dynamic radio resource managementand data packet scheduling, and mobility management.

In accordance with some embodiments, the UEs XS01 and XS02 can beconfigured to communicate using Orthogonal Frequency-DivisionMultiplexing (OFDM) communication signals with each other or with any ofthe RAN nodes XS11 and XS12 over a multicarrier communication channel inaccordance with various communication techniques, such as, but notlimited to, an Orthogonal Frequency-Division Multiple Access (OFDMA)communication technique (e.g., for downlink communications) or a SingleCarrier Frequency Division Multiple Access (SC-FDMA) communicationtechnique (e.g., for uplink and ProSe or sidelink communications),although the scope of the embodiments is not limited in this respect.The OFDM signals can comprise a plurality of orthogonal subcarriers.

In some embodiments, a downlink resource grid can be used for downlinktransmissions from any of the RAN nodes XS11 and XS12 to the UEs XS01and XS02, while uplink transmissions can utilize similar techniques. Thegrid can be a time-frequency grid, called a resource grid ortime-frequency resource grid, which is the physical resource in thedownlink in each slot. Such a time-frequency plane representation is acommon practice for OFDM systems, which makes it intuitive for radioresource allocation. Each column and each row of the resource gridcorresponds to one OFDM symbol and one OFDM subcarrier, respectively.The duration of the resource grid in the time domain corresponds to oneslot in a radio frame. The smallest time-frequency unit in a resourcegrid is denoted as a resource element. Each resource grid comprises anumber of resource blocks, which describe the mapping of certainphysical channels to resource elements. Each resource block comprises acollection of resource elements; in the frequency domain, this mayrepresent the smallest quantity of resources that currently can beallocated. There are several different physical downlink channels thatare conveyed using such resource blocks.

The physical downlink shared channel (PDSCH) may carry user data andhigher-layer signaling to the UEs XS01 and XS02. The physical downlinkcontrol channel (PDCCH) may carry information about the transport formatand resource allocations related to the PDSCH channel, among otherthings. It may also inform the UEs XS01 and XS02 about the transportformat, resource allocation, and H-ARQ (Hybrid Automatic Repeat Request)information related to the uplink shared channel. Typically, downlinkscheduling (assigning control and shared channel resource blocks to theUE XS01 and XS02 within a cell) may be performed at any of the RAN nodesXS11 and XS12 based on channel quality information fed back from any ofthe UEs XS01 and XS02. The downlink resource assignment information maybe sent on the PDCCH used for (e.g., assigned to) each of the UEs XS01and XS02.

The PDCCH may use control channel elements (CCEs) to convey the controlinformation. Before being mapped to resource elements, the PDCCHcomplex-valued symbols may first be organized into quadruplets, whichmay then be permuted using a sub-block interleaver for rate matching.Each PDCCH may be transmitted using one or more of these CCEs, whereeach CCE may correspond to nine sets of four physical resource elementsknown as resource element groups (REGs). Four Quadrature Phase ShiftKeying (QPSK) symbols may be mapped to each REG. The PDCCH can betransmitted using one or more CCEs, depending on the size of thedownlink control information (DCI) and the channel condition. There canbe four or more different PDCCH formats defined in LTE with differentnumbers of CCEs (e.g., aggregation level, L=1, 2, 4, or 8).

Some embodiments may use concepts for resource allocation for controlchannel information that are an extension of the above-describedconcepts. For example, some embodiments may utilize an enhanced physicaldownlink control channel (EPDCCH) that uses PDSCH resources for controlinformation transmission. The EPDCCH may be transmitted using one ormore enhanced control channel elements (ECCEs). Similar to above, eachECCE may correspond to nine sets of four physical resource elementsknown as enhanced resource element groups (EREGs). An ECCE may haveother numbers of EREGs in some situations.

The RAN XS10 is shown to be communicatively coupled to a core network(CN) XS20—via an S1 interface XS13. In embodiments, the CN XS20 may bean evolved packet core (EPC) network, a NextGen Packet Core (NPC)network, or some other type of CN. In this embodiment the S1 interfaceXS13 is split into two parts: the S1-U interface XS14, which carriestraffic data between the RAN nodes XS11 and XS12 and the serving gateway(S-GW) XS22, and the SI-mobility management entity (MME) interface XS15,which is a signaling interface between the RAN nodes XS11 and XS12 andMMEs XS21.

In this embodiment, the CN XS20 comprises the MMEs XS21, the S-GW XS22,the Packet Data Network (PDN) Gateway (P-GW) XS23, and a home subscriberserver (HSS) XS24. The MMEs XS21 may be similar in function to thecontrol plane of legacy Serving General Packet Radio Service (GPRS)Support Nodes (SGSN). The MMEs XS21 may manage mobility aspects inaccess such as gateway selection and tracking area list management. TheHSS XS24 may comprise a database for network users, includingsubscription-related information to support the network entities'handling of communication sessions. The CN XS20 may comprise one orseveral HSSs XS24, depending on the number of mobile subscribers, on thecapacity of the equipment, on the organization of the network, etc. Forexample, the HSS XS24 can provide support for routing/roaming,authentication, authorization, naming/addressing resolution, locationdependencies, etc.

The S-GW XS22 may terminate the S1 interface XS13 towards the RAN XS10,and routes data packets between the RAN XS10 and the CN XS20. Inaddition, the S-GW XS22 may be a local mobility anchor point forinter-RAN node handovers and also may provide an anchor for inter-3GPPmobility. Other responsibilities may include lawful intercept, charging,and some policy enforcement.

The P-GW XS23 may terminate an SGi interface toward a PDN. The P-GW XS23may route data packets between the EPC network XS23 and externalnetworks such as a network including the application server XS30(alternatively referred to as application function (AF)) via an InternetProtocol (IP) interface XS25. Generally, the application server XS30 maybe an element offering applications that use IP bearer resources withthe core network (e.g., UMTS Packet Services (PS) domain, LTE PS dataservices, etc.). In this embodiment, the P-GW XS23 is shown to becommunicatively coupled to an application server XS30 via an IPcommunications interface XS25. The application server XS30 can also beconfigured to support one or more communication services (e.g.,Voice-over-Internet Protocol (VoIP) sessions, PTT sessions, groupcommunication sessions, social networking services, etc.) for the UEsXS01 and XS02 via the CN XS20.

The P-GW XS23 may further be a node for policy enforcement and chargingdata collection. Policy and Charging Enforcement Function (PCRF) XS26 isthe policy and charging control element of the CN XS20. In a non-roamingscenario, there may be a single PCRF in the Home Public Land MobileNenvork (HPLMN) associated with a UE's Internet Protocol ConnectivityAccess Network (IP-CAN) session. In a roaming scenario with localbreakout of traffic, there may be two PCRFs associated with a UE'sIP-CAN session: a Home PCRF (H-PCRF) within an HPLMN and a Visited PCRF(V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRFXS26 may be communicatively coupled to the application server XS30 viathe P-GW XS23. The application server XS30 may signal the PCRF XS26 toindicate a new service flow and select the appropriate Quality ofService (QoS) and charging parameters. The PCRF XS26 may provision thisrule into a Policy and Charging Enforcement Function (PCEF) (not shown)with the appropriate traffic flow template (TFT) and QoS class ofidentifier (QCI), which commences the QoS and charging as specified bythe application server XS30.

FIG. 15 illustrates example components of a device XT00 in accordancewith some embodiments. In some embodiments, the device XT00 may includeapplication circuitry XT02, baseband circuitry XT04, Radio Frequency(RF) circuitry XT06, front-end module (FEM) circuitry XT08, one or moreantennas XT10, and power management circuitry (PMC) XT12 coupledtogether at least as shown. The components of the illustrated deviceXT00 may be included in a UE or a RAN node. In some embodiments, thedevice XT00 may include less elements (e.g., a RAN node may not utilizeapplication circuitry XT02, and instead include a processor/controllerto process IP data received from an EPC). In some embodiments, thedevice XT00 may include additional elements such as, for example,memory/storage, display, camera, sensor, or input/output (I/O)interface. In other embodiments, the components described below may beincluded in more than one device (e.g., said circuitries may beseparately included in more than one device for Cloud-RAN (C-RAN)implementations).

The application circuitry XT02 may include one or more applicationprocessors. For example, the application circuitry XT02 may includecircuitry such as, but not limited to, one or more single-core ormulti-core processors. The processor(s) may include any combination ofgeneral-purpose processors and dedicated processors (e.g., graphicsprocessors, application processors, etc.). The processors may be coupledwith or may include memory/storage and may be configured to executeinstructions stored in the memory/storage to enable various applicationsor operating systems to run on the device XT00. In some embodiments,processors of application circuitry XT02 may process IP data packetsreceived from an EPC.

The baseband circuitry XT04 may include circuitry such as, but notlimited to, one or more single-core or multi-core processors. Thebaseband circuitry XT04 may include one or more baseband processors orcontrol logic to process baseband signals received from a receive signalpath of the RF circuitry XT06 and to generate baseband signals for atransmit signal path of the RF circuitry XT06. Baseband processingcircuitry XT04 may interface with the application circuitry XT02 forgeneration and processing of the baseband signals and for controllingoperations of the RF circuitry XT06. For example, in some embodiments,the baseband circuitry XT04 may include a third generation (3G) basebandprocessor XT04A, a fourth generation (4G) baseband processor XT04B, afifth generation (5G) baseband processor XT04C, or other basebandprocessor(s) XT04D for other existing generations, generations indevelopment or to be developed in the future (e.g., second generation(2G), sixth generation (6G), etc.). The baseband circuitry XT04 (e.g.,one or more of baseband processors XT04A-D) may handle various radiocontrol functions that enable communication with one or more radionetworks via the RF circuitry XT06. In other embodiments, some or all ofthe functionality of baseband processors XT04A-D may be included inmodules stored in the memory XT04G and executed via a Central ProcessingUnit (CPU) XT04E. The radio control functions may include, but are notlimited to, signal modulation/demodulation, encoding/decoding, radiofrequency shifting, etc. In some embodiments, modulation/demodulationcircuitry of the baseband circuitry XT04 may include Fast-FourierTransform (FFT), precoding, or constellation mapping/demappingfunctionality. In some embodiments, encoding/decoding circuitry of thebaseband circuitry XT04 may include convolution, tail-bitingconvolution, turbo, Viterbi, or Low Density Parity Check (LDPC)encoder/decoder functionality. Embodiments of modulation/demodulationand encoder/decoder functionality are not limited to these examples andmay include other suitable functionality in other embodiments.

In some embodiments, the baseband circuitry XT04 may include one or moreaudio digital signal processor(s) (DSP) XT04F. The audio DSP(s) XT04Fmay include elements for compression/decompression and echo cancellationand may include other suitable processing elements in other embodiments.Components of the baseband circuitry XT04 may be suitably combined in asingle chip, a single chipset, or disposed on a same circuit board insome embodiments. In some embodiments, some or all of the constituentcomponents of the baseband circuitry XT04 and the application circuitryXT02 may be implemented together such as, for example, on a system on achip (SOC).

In some embodiments, the baseband circuitry XT04 may provide forcommunication compatible with one or more radio technologies. Forexample, in some embodiments, the baseband circuitry XT04 may supportcommunication with an evolved universal terrestrial radio access network(EUTRAN) or other wireless metropolitan area networks (WMAN), a wirelesslocal area network (WLAN), a wireless personal area network (WPAN).Embodiments in which the baseband circuitry XT04 is configured tosupport radio communications of more than one wireless protocol may bereferred to as multi-mode baseband circuitry.

RF circuitry XT06 may enable communication with wireless networks usingmodulated electromagnetic radiation through a non-solid medium. Invarious embodiments, the RF circuitry XT06 may include switches,filters, amplifiers, etc. to facilitate the communication with thewireless network. RF circuitry XT06 may include a receive signal pathwhich may include circuitry to down-convert RF signals received from theFEM circuitry XT08 and provide baseband signals to the basebandcircuitry XT04. RF circuitry XT06 may also include a transmit signalpath which may include circuitry to up-convert baseband signals providedby the baseband circuitry XT04 and provide RF output signals to the FEMcircuitry XT08 for transmission.

In some embodiments, the receive signal path of the RF circuitry XT06may include mixer circuitry XT06 a, amplifier circuitry XT06 b andfilter circuitry XT06 c. In some embodiments, the transmit signal pathof the RF circuitry XT06 may include filter circuitry XT06 c and mixercircuitry XT06 a. RF circuitry XT06 may also include synthesizercircuitry XT06 d for synthesizing a frequency for use by the mixercircuitry XT06 a of the receive signal path and the transmit signalpath. In some embodiments, the mixer circuitry XT06 a of the receivesignal path may be configured to down-convert RF signals received fromthe FEM circuitry XT08 based on the synthesized frequency provided bysynthesizer circuitry XT06 d. The amplifier circuitry XT06 b may beconfigured to amplify the down-converted signals and the filtercircuitry XT06 c may be a low-pass filter (LPF) or band-pass filter(BPF) configured to remove unwanted signals from the down-convertedsignals to generate output baseband signals. Output baseband signals maybe provided to the baseband circuitry XT04 for further processing. Insome embodiments, the output baseband signals may be zero-frequencybaseband signals, although this is not a requirement. In someembodiments, mixer circuitry XT06 a of the receive signal path maycomprise passive mixers, although the scope of the embodiments is notlimited in this respect.

In some embodiments, the mixer circuitry XT06 a of the transmit signalpath may be configured to up-convert input baseband signals based on thesynthesized frequency provided by the synthesizer circuitry XT06 d togenerate RF output signals for the FEM circuitry XT08. The basebandsignals may be provided by the baseband circuitry XT04 and may befiltered by filter circuitry XT06 c.

In some embodiments, the mixer circuitry XT06 a of the receive signalpath and the mixer circuitry XT06 a of the transmit signal path mayinclude two or more mixers and may be arranged for quadraturedownconversion and upconversion, respectively. In some embodiments, themixer circuitry XT06 a of the receive signal path and the mixercircuitry XT06 a of the transmit signal path may include two or moremixers and may be arranged for image rejection (e.g., Hartley imagerejection). In some embodiments, the mixer circuitry XT06 a of thereceive signal path and the mixer circuitry XT06 a of the transmitsignal path may be arranged for direct downconversion and directupconversion, respectively. In some embodiments, the mixer circuitryXT06 a of the receive signal path and the mixer circuitry XT06 a of thetransmit signal path may be configured for super-heterodyne operation.

In some embodiments, the output baseband signals and the input basebandsignals may be analog baseband signals, although the scope of theembodiments is not limited in this respect. In some alternateembodiments, the output baseband signals and the input baseband signalsmay be digital baseband signals. In these alternate embodiments, the RFcircuitry XT06 may include analog-to-digital converter (ADC) anddigital-to-analog converter (DAC) circuitry and the baseband circuitryXT04 may include a digital baseband interface to communicate with the RFcircuitry XT06.

In some dual-mode embodiments, a separate radio IC circuitry may beprovided for processing signals for each spectrum, although the scope ofthe embodiments is not limited in this respect.

In some embodiments, the synthesizer circuitry XT06 d may be afractional-N synthesizer or a fractional N/N+1 synthesizer, although thescope of the embodiments is not limited in this respect as other typesof frequency synthesizers may be suitable. For example, synthesizercircuitry XT06 d may be a delta-sigma synthesizer, a frequencymultiplier, or a synthesizer comprising a phase-locked loop with afrequency divider.

The synthesizer circuitry XT06 d may be configured to synthesize anoutput frequency for use by the mixer circuitry XT06 a of the RFcircuitry XT06 based on a frequency input and a divider control input.In some embodiments, the synthesizer circuitry XT06 d may be afractional N/N+1 synthesizer.

In some embodiments, frequency input may be provided by a voltagecontrolled oscillator (VCO), although that is not a requirement. Dividercontrol input may be provided by either the baseband circuitry XT04 orthe applications processor XT02 depending on the desired outputfrequency. In some embodiments, a divider control input (e.g., N) may bedetermined from a look-up table based on a channel indicated by theapplications processor XT02.

Synthesizer circuitry XT06 d of the RF circuitry XT06 may include adivider, a delay-locked loop (DLL), a multiplexer and a phaseaccumulator. In some embodiments, the divider may be a dual modulusdivider (DMD) and the phase accumulator may be a digital phaseaccumulator (DPA). In some embodiments, the DMD may be configured todivide the input signal by either N or N+1 (e.g., based on a carry out)to provide a fractional division ratio. In some example embodiments, theDLL may include a set of cascaded, tunable, delay elements, a phasedetector, a charge pump and a D-type flip-flop. In these embodiments,the delay elements may be configured to break a VCO period up into Ndequal packets of phase, where Nd is the number of delay elements in thedelay line. In this way, the DLL provides negative feedback to helpensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuitry XT06 d may be configured togenerate a carrier frequency as the output frequency, while in otherembodiments, the output frequency may be a multiple of the carrierfrequency (e.g., twice the carrier frequency, four times the carrierfrequency) and used in conjunction with quadrature generator and dividercircuitry to generate multiple signals at the carrier frequency withmultiple different phases with respect to each other. In someembodiments, the output frequency may be a LO frequency (fLO). In someembodiments, the RF circuitry XT06 may include an IQ/polar converter.

FEM circuitry XT08 may include a receive signal path which may includecircuitry configured to operate on RF signals received from one or moreantennas XT10, amplify the received signals and provide the amplifiedversions of the received signals to the RF circuitry XT06 for furtherprocessing. FEM circuitry XT08 may also include a transmit signal pathwhich may include circuitry configured to amplify signals fortransmission provided by the RF circuitry XT06 for transmission by oneor more of the one or more antennas XT10. In various embodiments, theamplification through the transmit or receive signal paths may be donesolely in the RF circuitry XT06, solely in the FEM XT08, or in both theRF circuitry XT06 and the FEM XT08.

In some embodiments, the FEM circuitry XT08 may include a TX/RX switchto switch between transmit mode and receive mode operation. The FEMcircuitry may include a receive signal path and a transmit signal path.The receive signal path of the FEM circuitry XT08 may include an LNA toamplify received RF signals and provide the amplified received RFsignals as an output (e.g., to the RF circuitry XT06). The transmitsignal path of the FEM circuitry XT08 may include a power amplifier (PA)to amplify input RF signals (e.g., provided by RF circuitry XT06), andone or more filters to generate RF signals for subsequent transmission(e.g., by one or more of the one or more antennas XT10).

In some embodiments, the PMC XT12 may manage power provided to thebaseband circuitry XT04. In particular, the PMC XT12 may controlpower-source selection, voltage scaling, battery charging, or DC-to-DCconversion. The PMC XT12 may often be included when the device XT00 iscapable of being powered by a battery, for example, when the device isincluded in a UE. The PMC XT12 may increase the power conversionefficiency while providing desirable implementation size and heatdissipation characteristics.

FIG. 15 shows the PMC XT12 coupled only with the baseband circuitryXT04. However, in other embodiments, the PMC XT12 may be additionally oralternatively coupled with, and perform similar power managementoperations for, other components such as, but not limited to,application circuitry XT02, RF circuitry XT06, or FEM XT08.

In some embodiments, the PMC XT12 may control, or otherwise be part of,various power saving mechanisms of the device XT00. For example, if thedevice XT00 is in an RRC_Connected state, where it is still connected tothe RAN node as it expects to receive traffic shortly, then it may entera state known as Discontinuous Reception Mode (DRX) after a period ofinactivity. During this state, the device XT00 may power down for briefintervals of time and thus save power.

If there is no data traffic activity for an extended period of time,then the device XT00 may transition off to an RRC_Idle state, where itdisconnects from the network and does not perform operations such aschannel quality feedback, handover, etc. The device XT00 goes into avery low power state and it performs paging where again it periodicallywakes up to listen to the network and then powers down again. The deviceXT00 may not receive data in this state, in order to receive data, itmust transition back to RRC_Connected state.

An additional power saving mode may allow a device to be unavailable tothe network for periods longer than a paging interval (ranging fromseconds to a few hours). During this time, the device is totallyunreachable to the network and may power down completely. Any data sentduring this time incurs a large delay and it is assumed the delay isacceptable.

Processors of the application circuitry XT02 and processors of thebaseband circuitry XT04 may be used to execute elements of one or moreinstances of a protocol stack. For example, processors of the basebandcircuitry XT04, alone or in combination, may be used to execute Layer 3,Layer 2, or Layer 1 functionality, while processors of the applicationcircuitry XT02 may utilize data (e.g., packet data) received from theselayers and further execute Layer 4 functionality (e.g., transmissioncommunication protocol (TCP) and user datagram protocol (UDP) layers).As referred to herein, Layer 3 may comprise a radio resource control(RRC) layer, described in further detail below. As referred to herein,Layer 2 may comprise a medium access control (MAC) layer, a radio linkcontrol (RLC) layer, and a packet data convergence protocol (PDCP)layer, described in further detail below. As referred to herein, Layer 1may comprise a physical (PHY) layer of a UE/RAN node, described infurther detail below.

FIG. 16 illustrates example interfaces of baseband circuitry inaccordance with some embodiments. As discussed above, the basebandcircuitry XT04 of FIG. 15 may comprise processors XT04A-XT04E and amemory XT04G utilized by said processors. Each of the processorsXT04A-XT04E may include a memory interface, XU04A-XU04E, respectively,to send/receive data to/from the memory XT04G.

The baseband circuitry XT04 may further include one or more interfacesto communicatively couple to other circuitries/devices, such as a memoryinterface XU12 (e.g., an interface to send/receive data to/from memoryexternal to the baseband circuitry XT04), an application circuitryinterface XU14 (e.g., an interface to send/receive data to/from theapplication circuitry XT02 of FIG. 15), an RF circuitry interface XU16(e.g., an interface to send/receive data to/from RF circuitry XT06 ofFIG. 15), a wireless hardware connectivity interface XU18 (e.g., aninterface to send/receive data to/from Near Field Communication (NFC)components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi®components, and other communication components), and a power managementinterface XU20 (e.g., an interface to send/receive power or controlsignals to/from the PMC XT12).

FIG. 17 is an illustration of a control plane protocol stack inaccordance with some embodiments. In this embodiment, a control planeXV00 is shown as a communications protocol stack between the UE XS01 (oralternatively, the UE XS02), the RAN node XS11 (or alternatively, theRAN node XS12), and the MME XS21.

The PHY layer XV01 may transmit or receive information used by the MAClayer XV02 over one or more air interfaces. The PHY layer XV01 mayfurther perform link adaptation or adaptive modulation and coding (AMC),power control, cell search (e.g., for initial synchronization andhandover purposes), and other measurements used by higher layers, suchas the RRC layer XV05. The PHY layer XV01 may still further performerror detection on the transport channels, forward error correction(FEC) coding/decoding of the transport channels, modulation/demodulationof physical channels, interleaving, rate matching, mapping onto physicalchannels, and Multiple Input Multiple Output (MIMO) antenna processing.

The MAC layer XV02 may perform mapping between logical channels andtransport channels, multiplexing of MAC service data units (SDUs) fromone or more logical channels onto transport blocks (TB) to be deliveredto PHY via transport channels, de-multiplexing MAC SDUs to one or morelogical channels from transport blocks (TB) delivered from the PHY viatransport channels, multiplexing MAC SDUs onto TBs, schedulinginformation reporting, error correction through hybrid automatic repeatrequest (HARD), and logical channel prioritization.

The RLC layer XV03 may operate in a plurality of modes of operation,including: Transparent Mode (TM), Unacknowledged Mode (UM), andAcknowledged Mode (AM). The RLC layer XV03 may execute transfer of upperlayer protocol data units (PDUs), error correction through automaticrepeat request (ARQ) for AM data transfers, and concatenation,segmentation and reassembly of RLC SDUs for UM and AM data transfers.The RLC layer XV03 may also execute re-segmentation of RLC data PDUs forAM data transfers, reorder RLC data PDUs for UM and AM data transfers,detect duplicate data for UM and AM data transfers, discard RLC SDUs forUM and AM data transfers, detect protocol errors for AM data transfers,and perform RLC re-establishment.

The PDCP layer XV04 may execute header compression and decompression ofIP data, maintain PDCP Sequence Numbers (SNs), perform in-sequencedelivery of upper layer PDUs at re-establishment of lower layers,eliminate duplicates of lower layer SDUs at re-establishment of lowerlayers for radio bearers mapped on RLC AM, cipher and decipher controlplane data, perform integrity protection and integrity verification ofcontrol plane data, control timer-based discard of data, and performsecurity operations (e.g., ciphering, deciphering, integrity protection,integrity verification, etc.).

The main services and functions of the RRC layer XV05 may includebroadcast of system information (e.g., included in Master InformationBlocks (MIBs) or System Information Blocks (SIBs) related to thenon-access stratum (NAS)), broadcast of system information related tothe access stratum (AS), paging, establishment, maintenance and releaseof an RRC connection between the DE and E-UTRAN (e.g., RRC connectionpaging, RRC connection establishment, RRC connection modification, andRRC connection release), establishment, configuration, maintenance andrelease of point to point Radio Bearers, security functions includingkey management, inter radio access technology (RAT) mobility, andmeasurement configuration for UE measurement reporting. Said MIBs andSIBs may comprise one or more information elements (IEs), which may eachcomprise individual data fields or data structures. In some embodiments,the RRC layer may provide the UEs XS01 and XS02 with configurations forthe antenna ports N for CSI-RS signal(s) and antenna ports K forcodebook(s) according to the various embodiments discussed herein.

The UE XS01 and the RAN node XS11 may utilize a Uu interface (e.g., anLTE-Uu interface) to exchange control plane data via a protocol stackcomprising the PHY layer XV01, the MAC layer XV02, the RLC layer XV03,the PDCP layer XV04, and the RRC layer XV05.

The non-access stratum (NAS) protocols XV06 form the highest stratum ofthe control plane between the UE XS01 and the MME XS21. The NASprotocols XV06 support the mobility of the UE XS01 and the sessionmanagement procedures to establish and maintain IP connectivity betweenthe UE XS01 and the P-GW XS23.

The S1 Application Protocol (S1-AP) layer XV15 may support the functionsof the S1 interface and comprise Elementary Procedures (EPs). An EP is aunit of interaction between the RAN node XS11 and the CN XS20. The S1-APlayer services may comprise two groups: UE-associated services and nonUE-associated services. These services perform functions including, butnot limited to: E-UTRAN Radio Access Bearer (E-RAB) management, UEcapability indication, mobility, NAS signaling transport, RANInformation Management (RIM), and configuration transfer.

The Stream Control Transmission Protocol (SCTP) layer (alternativelyreferred to as the SCTP/IP layer) XV14 may ensure reliable delivery ofsignaling messages between the RAN node XS11 and the MME XS21 based, inpart, on the IP protocol, supported by the IP layer XV13. The L2 layerXV12 and the L1 layer XV11 may refer to communication links (e.g., wiredor wireless) used by the RAN node and the MME to exchange information.

The RAN node XS11 and the MME XS21 may utilize an S1-MME interface toexchange control plane data via a protocol stack comprising the L1 layerXV11, the L2 layer XV12, the IP layer XV13, the SCTP layer XV14, and theSI-AP layer XV15.

FIG. 18 is an illustration of a user plane protocol stack in accordancewith some embodiments. In this embodiment, a user plane XW00 is shown asa communications protocol stack between the UE XS01 (or alternatively,the UE XS02), the RAN node XS11 (or alternatively, the RAN node XS12),the S-GW XS22, and the P-GW XS23. The user plane XW00 may utilize atleast some of the same protocol layers as the control plane XV00. Forexample, the UE XS01 and the RAN node XS11 may utilize a Uu interface(e.g., an LTE-Uu interface) to exchange user plane data via a protocolstack comprising the PHY layer XV01, the MAC layer XV02, the RLC layerXV03, the PDCP layer XV04.

The General Packet Radio Service (GPRS) Tunneling Protocol for the userplane (GTP-U) layer XW04 may be used for carrying user data within theGPRS core network and between the radio access network and the corenetwork. The user data transported can be packets in any of IPv4, IPv6,or PPP formats, for example. The UDP and IP security (UDP/IP) layer XW03may provide checksums for data integrity, port numbers for addressingdifferent functions at the source and destination, and encryption andauthentication on the selected data flows. The RAN node XS11 and theS-GW XS22 may utilize an S1-U interface to exchange user plane data viaa protocol stack comprising the L1 layer XV11, the L2 layer XV12, theUDP/IP layer XW03, and the GTP-U layer XW04. The S-GW XS22 and the P-GWXS23 may utilize an S5/S8a interface to exchange user plane data via aprotocol stack comprising the L1 layer XV11, the L2 layer XV12, theUDP/IP layer XW03, and the GTP-U layer XW04. As discussed above withrespect to FIG. 17, NAS protocols support the mobility of the UE XS01and the session management procedures to establish and maintain IPconnectivity between the UE XS01 and the P-GW XS23.

FIG. 19 illustrates components of a core network in accordance with someembodiments. The components of the CN XS20 may be implemented in onephysical node or separate physical nodes including components to readand execute instructions from a machine-readable or computer-readablemedium (e.g., a non-transitory machine-readable storage medium). In someembodiments, Network Functions Virtualization (NFV) is utilized tovirtualize any or all of the above described network node functions viaexecutable instructions stored in one or more computer readable storagemediums (described in further detail below). A logical instantiation ofthe CN XS20 may be referred to as a network slice XX01. A logicalinstantiation of a portion of the CN XS20 may be referred to as anetwork sub-slice XX02 (e.g., the network sub-slice XX02 is shown toinclude the PGW XS23 and the PCRF XS26).

NFV architectures and infrastructures may be used to virtualize one ormore network functions, alternatively performed by proprietary hardware,onto physical resources comprising a combination of industry-standardserver hardware, storage hardware, or switches. In other words, NFVsystems can be used to execute virtual or reconfigurable implementationsof one or more EPC components/functions.

FIG. 20 is a block diagram illustrating components, according to someexample embodiments, able to read instructions from a machine-readableor computer-readable medium (e.g., a non-transitory machine-readablestorage medium) and perform any one or more of the methodologiesdiscussed herein. Specifically, FIG. 20 shows a diagrammaticrepresentation of hardware resources XZ00 including one or moreprocessors (or processor cores) XZ10, one or more memory/storage devicesXZ20, and one or more communication resources XZ30, each of which may becommunicatively coupled via a bus XZ40. For embodiments where nodevirtualization (e.g., NFV) is utilized, a hypervisor XZ02 may beexecuted to provide an execution environment for one or more networkslices/sub-slices to utilize the hardware resources XZ00.

The processors XZ10 (e.g., a central processing unit (CPU), a reducedinstruction set computing (RISC) processor, a complex instruction setcomputing (CISC) processor, a graphics processing unit (GPU), a digitalsignal processor (DSP) such as a baseband processor, an applicationspecific integrated circuit (ASIC), a radio-frequency integrated circuit(RFIC), another processor, or any suitable combination thereof) mayinclude, for example, a processor XZ12 and a processor XZ14.

The memory/storage devices XZ20 may include main memory, disk storage,or any suitable combination thereof. The memory/storage devices XZ20 mayinclude, but are not limited to any type of volatile or non-volatilememory such as dynamic random access memory (DRAM), static random-accessmemory (SRAM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), Flashmemory, solid-state storage, etc.

The communication resources XZ30 may include interconnection or networkinterface components or other suitable devices to communicate with oneor more peripheral devices XZ04 or one or more databases XZ06 via anetwork XZ08. For example, the communication resources XZ30 may includewired communication components (e.g., for coupling via a UniversalSerial Bus (USB)), cellular communication components, NFC components,Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components,and other communication components.

Instructions XZ50 may comprise software, a program, an application, anapplet, an app, or other executable code for causing at least any of theprocessors XZ10 to perform any one or more of the methodologiesdiscussed herein. The instructions XZ50 may reside, completely orpartially, within at least one of the processors XZ10 (e.g., within theprocessor's cache memory), the memory/storage devices XZ20, or anysuitable combination thereof. Furthermore, any portion of theinstructions XZ50 may be transferred to the hardware resources XZ00 fromany combination of the peripheral devices XZ04 or the databases XZ06.Accordingly, the memory of processors XZ10, the memory/storage devicesXZ20, the peripheral devices XZ04, and the databases XZ06 are examplesof computer-readable and machine-readable media.

In some embodiments, the electronic device(s), network(s), system(s),chip(s) or component(s), or portions or implementations thereof, ofFIGS. 14-20, or some other figure herein may be configured to performone or more processes, techniques, or methods as described herein, orportions thereof.

Example 1 may include a computer-readable medium having instructionsstored thereof, wherein the instructions, in response to execution by auser equipment (UE), cause the UE to store a rank indicator (RI), aprecoding matrix index (PMI), and a channel quality indicator (CQI) ofchannel state information (CSI) for the UE, concatenate the RI, the PMI,and the CQI to produce a concatenated CSI element, generate a CSI reportthat includes the concatenated CSI element, and cause the CSI report tobe transmitted to a base station within a single slot.

Example 2 may include the computer-readable medium of example 1, whereinthe instructions further cause the UE to concatenate the PMI and the CQIto produce a PMI-CQI value, encode the PMI-CQI value, and encode the RI,wherein to concatenate the RI, the PMI, and the CQI includes toconcatenate the encoded PMI-CQI value with the encoded RI.

Example 3 may include the computer-readable medium of example 2, whereinto concatenate the encoded PMI-CQI value with the encoded RI includes tomultiplex and interleave the encoded PMI-CQI value with the encoded RI.

Example 4 may include the computer-readable medium of example 2, whereinto cause the CSI report to be transmitted includes to map each encodedbit of the encoded PMI-CQI value to a different physical uplink controlchannel (PUCCH) symbol from each encoded bit of the encoded RI.

Example 5 may include the computer-readable medium of example 2, whereinto cause the CSI report to be transmitted includes to map each encodedbit of the encoded PMI-CQI value to a different physical uplink controlchannel (PUCCH) format from each encoded bit of the encoded RI.

Example 6 may include the computer-readable medium of example 2, whereinan encoding rate of the PMI-CQI value is greater than an encoding rateof the RI.

Example 7 may include the computer-readable medium of any of examples1-6, wherein the instructions further cause the UE to encode theconcatenated CSI element, and wherein the concatenated CSI elementincluded in the CSI report is encoded.

Example 8 may include the apparatus of any of examples 1-6, wherein theinstructions further cause the UE to encode the RI by Reed-Muller code,and encode the PMI and the CQI by polar code.

Example 9 may include the apparatus of any of examples 1-6, wherein theinstructions further cause the UE to encode at least a portion of the RIusing a demodulation reference signal (DMRS) sequence.

Example 10 may include the apparatus of any of examples 1-6, wherein theCSI report further includes one or more cyclic redundancy check (CRC)bits.

Example 11 may include the apparatus of any of examples 1-6, wherein theinstructions further cause the UE to generate a joint index for the RIand the PMI, wherein to concatenate the RI, the PMI, and the CQIincludes to concatenate the joint index with the CQI.

Example 12 may include the apparatus of example 11, wherein theinstructions further cause the UE to encode the joint index, and encodethe CQI, wherein to concatenate the RI, the PMI and the CQI includes toconcatenate the encoded joint index with the encoded CQI.

Example 13 may include the apparatus of example 12, wherein toconcatenate the encoded joint index with the encoded CQI includes tomultiplex and interleave the encoded joint index with the encoded CQI.

Example 14 may include an apparatus for a base station (BS), comprisingcircuitry to identify a transmission associated with a rank indicator(RI) value received from a user equipment (UE), determine channel stateinformation (CSI) from the transmission, and verify validity of the CSIbased on a characteristic of the transmission, and memory to store theCSI.

Example 15 may include the apparatus of example 14 or any other exampleherein, wherein the transmission comprises a CSI report, to determinethe CSI includes to decode the CSI report via a decoding procedureassociated with a certain RI value to produce the CSI, and to verify thevalidity of the CSI includes to compare the CSI with one or more cyclicredundancy check (CRC) bits to determine the validity of the CSI.

Example 16 may include the apparatus of example 15 or any other exampleherein, wherein the circuitry, in response to determination that the CSIis invalid, is further to decode the CSI report via one or more otherdecoding procedures, each of the one or more other decoding proceduresassociated with other corresponding RI values, to produce one or moredecoded CSI reports, and compare CSI of each of the decoded CSI reportswith the one or more CRC bits to determine a one of the decoded CSIreports that is valid, and the memory to store the CSI of the one of thedecoded CSI reports.

Example 17 may include the apparatus of any of examples 14-16 or anyother example herein, wherein the transmission comprises a demodulationreference signal (DMRS), to determine the CSI includes to compare asequence of the DMRS with a DMRS sequence associated with a certain RIvalue, and to verify the validity of the CSI includes to determine asignal to interference and noise ratio (SINR) associated with the DMRSsequence based on channel estimation, and compare the SINR to one ormore SINRs associated with other DMRS sequences to determine thevalidity of the CSI.

Example 18 may include the apparatus of example 17 or any other exampleherein, wherein the circuitry, in response to determination that the CSIis invalid, is further to determine SINRs associated with each of theother DMRS sequences, and identify one DMRS sequence of the other DMRSsequences with a highest SINR, and determine an RI associated with theone DMRS sequence, and the memory is to store the RI associated with theone DMRS sequence.

Example 19 may include an apparatus for a user equipment (UE),comprising circuitry to identify an indication of a subset of antennaports of a base station, perform channel measurements on the subset, andcalculate channel state information (CSI) based on the channelmeasurements, and memory to store the CSI.

Example 20 may include the apparatus of example 19, wherein theindication of the subset of antenna ports includes an indication of anumber of antenna ports in a first dimension and an indication of anumber of antenna ports in a second dimension that produce the subset ofantenna ports.

Example 21 may include the apparatus of any of examples 19 or 20 or anyother example herein, wherein the circuitry is further to determine acodeword from a codebook based on the CSI, and generate a CSI report fortransmission to the base station, wherein the CSI report includes thecodeword, and the memory is to store the codeword.

Example 22 may include the apparatus of any of examples 19 or 20 or anyother example herein, wherein a number of antenna ports within thesubset is based on a number of antenna ports supported by the UE forchannel measurement.

Example 23 may include an apparatus for a base station, comprising meansfor generating a message for transmission to a user equipment (UE),wherein the message includes an indication of a subset of antenna portsof the base station to be utilized by the UE for channel measurement,means for generating a channel state information reference signal(CSI-RS) for transmission on the subset of antenna ports for the UE,means for identifying channel state information (CSI) received from theUE, and means for storing the CSI.

Example 24 may include the apparatus of example 23, wherein the messagethat includes the indication of the subset includes an indication of anumber of antenna ports in a first dimension and an indication of anumber of antenna ports in a second dimension.

Example 25 may include the apparatus of any of examples 23 or 24,further comprising means for identifying a precoding matrix indicator(PMI) included in the CSI, means for determining precoding to beperformed for the UE based on the PMI, and means for applying theprecoding to transmissions sent from the subset of the antenna ports tothe UE.

Example 26 may include a method comprising storing a rank indicator(RI), a precoding matrix index (PMI), and a channel quality indicator(CQI) of channel state information (CSI) for the UE, concatenating theRI, the PMI, and the CQI to produce a concatenated CSI element,generating a CSI report that includes the concatenated CSI element, andcausing the CSI report to be transmitted to a base station within asingle slot.

Example 27 may include the method of example 26 or any other exampleherein, further comprising concatenating the PMI and the CQI to producea PMI-CQI value, encode the PMI-CQI value, and encoding the RI, whereinconcatenating the RI, the PMI, and the CQI includes concatenating theencoded PMI-CQI value with the encoded RI.

Example 28 may include the method of example 27 or any other exampleherein, wherein concatenating the encoded PMI-CQI value with the encodedRI includes multiplexing and interleaving the encoded PMI-CQI value withthe encoded RI.

Example 29 may include the method of example 27 or any other exampleherein, wherein causing the CSI report to be transmitted includesmapping each encoded bit of the encoded PMI-CQI value to a differentphysical uplink control channel (PUCCH) symbol from each encoded bit ofthe encoded RI.

Example 30 may include the method of example 27 or any other exampleherein, wherein causing the CSI report to be transmitted includesmapping each encoded bit of the encoded PMI-CQI value to a differentphysical uplink control channel (PUCCH) format from each encoded bit ofthe encoded RI.

Example 31 may include the method of example 27 or any other exampleherein, wherein an encoding rate of the PMI-CQI value is greater than anencoding rate of the RI.

Example 32 may include the method of any of examples 26-31 or any otherexample herein, further comprising encoding the concatenated CSIelement, and wherein the concatenated CSI element included in the CSIreport is encoded.

Example 33 may include the method of any of examples 26-31 or any otherexample herein, further comprising encoding the RI by Reed-Muller code,and encoding the PMI and the CQI by polar code.

Example 34 may include the method of any of examples 26-31 or any otherexample herein, further comprising encoding at least a portion of the RIusing a demodulation reference signal (DMRS) sequence.

Example 35 may include the method of any of examples 26-31 or any otherexample herein, wherein the CSI report further includes one or morecyclic redundancy check (CRC) bits.

Example 36 may include the method of any of examples 26-31 or any otherexample herein, further comprising generating a joint index for the RIand the PMI, wherein concatenating the RI, the PMI, and the CQI includesconcatenating the joint index with the CQI.

Example 37 may include the method of example 36 or any other exampleherein, further comprising encoding the joint index, and encoding theCQI, wherein concatenating the RI, the PMI and the CQI includesconcatenating the encoded joint index with the encoded CQI.

Example 38 may include the method of example 37 or any other exampleherein, wherein concatenating the encoded joint index with the encodedCQI includes multiplexing and interleaving the encoded joint index withthe encoded CQI.

Example 39 may include an method, comprising identifying a transmissionassociated with a rank indicator (RI) value received from a userequipment (UE), determining channel state information (CSI) from thetransmission, verifying validity of the CSI based on a characteristic ofthe transmission, and storing the CSI.

Example 40 may include the method of example 39 or any other exampleherein, wherein the transmission comprises a CSI report, determining theCSI includes decoding the CSI report via a decoding procedure associatedwith a certain RI value to produce the CSI, and verifying the validityof the CSI includes to compare the CSI with one or more cyclicredundancy check (CRC) bits to determine the validity of the CSI.

Example 41 may include the method of example 40 or any other exampleherein, further comprising decoding, in response to determination thatthe CSI is invalid, the CSI report via one or more other decodingprocedures, each of the one or more other decoding procedures associatedwith other corresponding RI values, to produce one or more decoded CSIreports, comparing CSI of each of the decoded CSI reports with the oneor more CRC bits to determine a one of the decoded CSI reports that isvalid, and storing the CSI of the one of the decoded CSI reports.

Example 42 may include the method of any of examples 39-41 or any otherexample herein, wherein the transmission comprises a demodulationreference signal (DMRS), determining the CSI includes comparing asequence of the DMRS with a DMRS sequence associated with a certain RIvalue, and verifying the validity of the CSI includes determining asignal to interference and noise ratio (SINR) associated with the DMRSsequence based on channel estimation and comparing the SINR to one ormore SINRs associated with other DMRS sequences to determine thevalidity of the CSI.

Example 43 may include the method of example 42 or any other exampleherein, further comprising determining, in response to determinationthat the CSI is invalid, SINRs associated with each of the other DMRSsequences, identifying one DMRS sequence of the other DMRS sequenceswith a highest SINR, determining an RI associated with the one DMRSsequence, and storing the RI associated with the one DMRS sequence.

Example 44 may include a method, comprising identifying an indication ofa subset of antenna ports of a base station, performing channelmeasurements on the subset, calculating channel state information (CSI)based on the channel measurements, and storing the CSI.

Example 45 may include the method of example 44, wherein the indicationof the subset of antenna ports includes an indication of a number ofantenna ports in a first dimension and an indication of a number ofantenna ports in a second dimension that produce the subset of antennaports.

Example 46 may include the method of any of examples 44 or 45 or anyother example herein, further comprising determining a codeword from acodebook based on the CSI, generating a CSI report for transmission tothe base station, wherein the CSI report includes the codeword, andstoring the codeword.

Example 47 may include the method of any of examples 44 or 45 or anyother example herein, wherein a number of antenna ports within thesubset is based on a number of antenna ports supported by the UE forchannel measurement.

Example 48 may include a method, comprising generating a message fortransmission to a user equipment (UE), wherein the message includes anindication of a subset of antenna ports of the base station to beutilized by the UE for channel measurement, generating a channel stateinformation reference signal (CSI-RS) for transmission on the subset ofantenna ports for the UE, identifying channel state information (CSI)received from the UE, and storing the CSI.

Example 49 may include the method of example 48 or any other exampleherein, wherein the message that includes the indication of the subsetincludes an indication of a number of antenna ports in a first dimensionand an indication of a number of antenna ports in a second dimension.

Example 50 may include the method of any of examples 48 or 49 or anyother example herein, further comprising identifying a precoding matrixindicator (PMI) included in the CSI, determining precoding to beperformed for the UE based on the PMI, and applying the precoding totransmissions sent from the subset of the antenna ports to the UE.

Example 51 may include an apparatus to perform any of the methods ofexamples 26-50 or some other example.

Example 52 may include a means to perform any of the methods of examples26-50 or some other example.

Example 53 may include a computer-readable medium having instructionsstored thereon, wherein the instructions, in response to execution by anapparatus, cause the apparatus to perform any of the methods of examples26-50 or some other example.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the disclosed embodiments ofthe disclosed device and associated methods without departing from thespirit or scope of the disclosure. Thus, it is intended that the presentdisclosure covers the modifications and variations of the embodimentsdisclosed above provided that the modifications and variations comewithin the scope of any claims and their equivalents.

What is claimed is:
 1. A base station, comprising: a transceiverconfigured to enable wireless communication with a user equipment (UE);and a processor communicatively coupled to the transceiver, andconfigured to: generate a message, wherein the message indicates asubset of antenna ports of the base station to be utilized by the UE forchannel measurement; transmit, using the transceiver, the message to theUE; generate a channel state information reference signal (CSI-RS);transmit, using the transceiver, the CSI-RS on the subset of antennaports to the UE; receive, using the transceiver, channel stateinformation (CSI) from the UE; and store the CSI.
 2. The base station ofclaim 1, wherein the message includes a first dimension indication and asecond dimension indication of the antenna ports of the base station. 3.The base station of claim 1, wherein the processor is further configuredto: determine a precoding matrix indicator (PMI) based on the CSI;determine a codeword based on the PMI; apply the codeword to a secondmessage; and transmit, using the transceiver, the second message to theUE on the subset of antenna ports.
 4. The base station of claim 3,wherein the second message is a physical downlink shared channel (PDSCH)message.
 5. The base station of claim 1, wherein the antenna ports ofthe base station have polarization slants of plus or minus 45 degrees.6. The base station of claim 1, wherein the processor is furtherconfigured to transmit higher layer signaling to the UE, wherein thehigher layer signaling indicates parameters to be measured by the UE,and wherein the parameters include a precoding matrix indicator (PMI).7. The base station of claim 1, wherein the processor is furtherconfigured to generate the message by: determining a capability of theUE; and determining the subset of the antenna ports based on thecapability.
 8. The base station of claim 1, wherein the processor isfurther configured to: determine a capability of a second UE; determinea second subset of antenna ports of the base station; and transmit theCSI-RS on the second subset of antenna ports to the second UE.
 9. Amethod of operating a base station comprising: generating a message thatindicates a subset of antenna ports of the base station to be utilizedby a user equipment (UE) for channel measurement; transmitting themessage to the UE; generating a channel state information referencesignal (CSI-RS); transmitting the CSI-RS on the subset of antenna portsto the UE; receiving channel state information (CSI) from the UE; andstoring the CSI.
 10. The method of claim 9, wherein the message includesa first dimension indication and a second dimension indication of theantenna ports of the base station.
 11. The method of claim 9 furthercomprising: determining a precoding matrix indicator (PMI) based on theCSI; determining a codeword based on the PMI; applying the codeword to asecond message; and transmitting, using the transceiver, the secondmessage to the UE via the subset of antenna ports.
 12. The method ofclaim 11, wherein the second message is a physical downlink sharedchannel (PDSCH) message.
 13. The method of claim 9, wherein the antennaports of the base station have polarization slants of plus or minus 45degrees.
 14. The method of claim 9 further comprising: transmittinghigher layer signaling to the UE, wherein the higher layer signalingindicates parameters to be measured by the UE, and wherein theparameters include a precoding matrix indicator (PMI).
 15. The method ofclaim 9, wherein generating the message further comprises: determining acapability of the UE; and determining the subset of the antenna portsbased on the capability.
 16. The method of claim 9 further comprising:determining a capability of a second UE; determining a second subset ofantenna ports of the base station; and transmitting the CSI-RS on thesecond subset of antenna ports to the second UE.
 17. A user equipment(UE), comprising: a transceiver configured to communicate with a basestation; and a processor communicatively coupled to the transceiver, andconfigured to: receive, using the transceiver, a message from the basestation, wherein the message indicates a subset of antenna ports of thebase station; receive, using the transceiver, a channel stateinformation reference signal (CSI-RS) from the subset of antenna portsof the base station; measure channel state information (CSI) based onthe CSI-RS; transmit, using the transceiver, a CSI report to the basestation.
 18. The UE of claim 17, wherein the processor is furtherconfigured to determine a precoding matrix indicator (PMI) based on theCSI, wherein the CSI report includes the PMI.
 19. The UE of claim 18,wherein the processor is further configured to determine the PMI bydetermining a codeword from a codebook based on the CSI.
 20. The UE ofclaim 18, wherein the processor is further configured to receive asecond message from the subset of antenna ports of the base station viaa physical downlink shared channel (PDSCH), wherein the second messageis precoded based on the PMI.